Outdoor lighting in old university campuses plays a dual role in ensuring nighttime safety and reconstructing spatial order, yet many existing campuses still suffer from fragmented lighting organization, ambiguous illumination zoning, and insufficient correspondence between lighting hierarchy and functional spatial structure. To address these problems, this study introduces the theories of spatial continuity and circle-layer organization into campus outdoor lighting planning, and takes Zone B of Chongqing University as a representative case. Based on field investigation, illuminance and luminance measurements, nighttime image comparison, functional zoning analysis, and pedestrian-flow heat-map observation, the study establishes a systematic lighting renewal framework for old campus environments characterized by complex spatial textures, historical architectural resources, and mixed nighttime activities. The investigation shows that the existing lighting environment in Zone B is dominated by scattered functional lighting and lacks an integrated spatial organization strategy. Most key building fa?ades are not independently illuminated and rely mainly on road lighting or interior light spill for nighttime visibility. Road lighting is uneven in several sections, while some pedestrian paths, green-space edges, and transitional areas contain dark zones or visual blind spots. In addition, abrupt changes in brightness and color temperature between adjacent spaces weaken the coherence of the nighttime visual sequence. These problems indicate that the existing lighting system has not yet formed a clear relationship between spatial hierarchy, behavioral intensity, cultural recognition, and visual guidance.To respond to these deficiencies, the study proposes a four-level circle-layer lighting system guided by two core design concepts: sequence synergy and hierarchy matching. Sequence synergy, derived from spatial continuity theory, emphasizes the construction of a continuous lighting sequence through the coordinated organization of buildings, roads, squares, landscape nodes, and pedestrian routes. In this framework, the road system is regarded as the linear skeleton that connects different spatial layers and supports visual continuity, wayfinding, and nighttime safety. Hierarchy matching, derived from circle-layer theory, emphasizes the establishment of differentiated lighting levels corresponding to functional attributes, spatial roles, and nighttime activity intensity. Rather than defining the campus core according to geometric centrality, this study identifies the lighting hierarchy on the basis of spatial use, pedestrian concentration, and behavioral characteristics. Accordingly, the sports field and surrounding gathering spaces are defined as the first layer, historical and cultural building areas as the second layer, teaching and research areas as the third layer, and living-service areas as the fourth layer.On this basis, a differentiated gradient control strategy is developed. For buildings, structures, entrance signs, sculptures, and other vertical interfaces, fa?ade luminance is designed to decrease progressively from the core to the periphery: no less than 8 cd/m2 in the first layer, 3-5 cd/m2 in the second layer, 2-3 cd/m2 in the third layer, and 0.5-1 cd/m2 in the fourth layer. Horizontal spaces such as sports venues, gathering squares, and roads are excluded from this fa?ade luminance controlsystem and should instead comply with the corresponding illuminance standards for functional activities and traffic safety. In terms of color temperature, the proposed strategy establishes a gradual transition from high arousal to high comfort. The first layer adopts neutral to slightly cool light of 4 000-4 500 K to enhance visual clarity, spatial recognition, and safety in high-density activity areas. The second layer uses 3 000 K warm-white light to reveal the texture of redbrick fa?ades and strengthen the historical atmosphere of the campus. The third layer adopts 4 000 K neutral warm-white light to support teaching, research, and road safety while maintaining a stable visual environment. The fourth layer uses warm yellow light of 2 700-3 000 K to reduce nighttime visual stimulation and create a quiet, comfortable, and low-interference residential atmosphere.The lighting method is also organized as a progressive spatial sequence. In the first layer, high-pole or medium-pole luminaires are used to provide broad lighting coverage for large-scale spaces, while concealed floodlights and buried luminaires highlight important nodes and reinforce the main visual axis. In the second layer, small-angle linear grazing, wall washing, and soft floodlighting are applied to emphasize material texture and establish cultural visual anchors. In the third layer, cut-off road luminaires, landscape lights, courtyard lights, and controlled interior light are combined to maintain basic visibility and spatial transition. In the fourth layer, low-position luminaires, shielded fixtures, grass lights, and concealed footlights are used to restrict light below the eye line, reduce spill light, and protect the residential environment from excessive visual disturbance. The results indicate that the proposed strategy can effectively address the lighting planning difficulties of old university campuses caused by complex spatial structures, mixed functional demands, and fragmented lighting facilities. By coordinating luminance hierarchy, color-temperature rhythm, lighting methods, and road-based spatial continuity, the strategy improves the visual connection between core and peripheral areas, enhances the nighttime recognition of key buildings, reduces visual discontinuity, and supports safer pedestrian movement. More importantly, the study demonstrates that the integration of spatial continuity theory and circle-layer theory can transform campus lighting planning from the isolated application of technical indicators into a systematic spatial design process that simultaneously considers safety, function, cultural expression, visual order, and environmental comfort. The proposed circle-layer boundaries and lighting parameters are not fixed templates, but can be recalibrated according to the functional layout, historical context, pedestrian behavior, and nighttime use characteristics of different campuses. Therefore, this research provides a theoretical framework and practical references for the stock renewal of outdoor lighting in comparable old university campuses.