Population aging is a nested process between individuals and their surrounding environment, where the resources, abilities, and behavioral preferences of the elderly are not solely determined by age, but rather by the aging process in their specific temporal and spatial environment, especially closely related to the built environment of residential areas that carry the daily physical activities of the elderly. China is currently in a historical process of rapid urbanization. For a long time, the planning and regulation strategies that focus on growth management and excessively pursue overall spatial performance have led to whether the construction environment of existing residential areas is suitable for the physical activity needs of the elderly? Has it played a crucial role in maintaining the basic behavioral functions and life rights of the elderly?Although existing research has measured the health benefits of built environments from a single functional perspective such as park green spaces, landscape design, and pedestrian suitability, there is relatively little analysis of their combined effects on individual health from the perspective of functional complementarity. In fact, the active intervention of elderly physical activity in the built environment of residential areas lies not only in the rational allocation and layout of public space resources, but also in the overall spatial creation of the built environment of residential areas to meet the “localized living” needs of the elderly population. From the perspective of physical activity for the elderly, public service facilities are the material basis for carrying out physical activity for the elderly, and the basic accessibility of service facilities is a prerequisite for the elderly to experience and use the built environment. The safety and landscape comfort of residential areas are also key factors that affect the duration and frequency of physical activity for the elderly in the built environment. Obviously, the realization of the health benefits of the built environment in residential areas lies in the complementarity of their functions, including highly coordinated and closely divided basic functions such as public services, transportation, leisure and entertainment, and residential work.This article takes Dalian as an example and constructs an input-output index system for the health benefits of residential built environments from the perspective of physical activity for the elderly. The data envelopment analysis constant return to scale (CRS) model is used to measure the health benefits of residential built environments in Dalian. The spatial differentiation is extracted through Global Molan’s I and local autocorrelation hot and cold spot analysis, and the driving factors of health benefits are detected using a geographic detector model. The research aims to quantitatively evaluate the efficiency of public space resource allocation in residential areas from the perspective of aging, in order to provide decision-making references for high-quality development of living environment under the background of stockplanning.The research results show that:1) the comprehensive efficiency of the built environment health benefits in residential areas in Dalian is relatively high, with an average comprehensive efficiency of 0.893. However, most residential areas have not reached the optimal efficiency, and insufficient scale efficiency is the main reason. There is a certain degree of high or low value spatial agglomeration of health benefits in the built environment of residential areas in Dalian. The hotspots of health benefits are mostly distributed in Shahekou District, while the cold and secondary cold spots are concentrated in the old urban areas of Ganjingzi District, such as Xiangheyuan, Lanxing Lane, and Hongqi Road residential areas. 2) The detection of health benefit factors shows that the road network, mainly composed of intersection density and road network density, is a key factor in the health benefits of the built environment in residential areas. Public restrooms, NDVI, rest and shelter facilities, as well as their spatial quality, are reinforcing factors, while safety in residential areas dominated by enclosed structures is a directional factor. 3) The built environment of residential areas in Dalian has insufficient supporting public service facilities or poor spatial layout, and the built environment of residential areas does not present a universal “dual” complementarity of functions. Among them, “dense road network small blocks”, complete public service facilities, and appropriate green spaces are effective ways to achieve good health benefits of the built environment of residential areas.