MMany researches have been done on the design of urban settlements under the target of stormwater management. However, the quantitative relationship between the morphological characteristics of green space and the runoff control objectives is still not discussed in depth. Firstly, it classifies the green space morphological characteristics and runoff water system characteristics in settlements. Then it employs Uwater Drainage software to simulate the rainfall runoff status of the site based on the design of a residential area in Chongqing. It illustrates the influence of residential building layout and green space morphology on rainfall runoff, and explores the composite structure of residential green space system integrating rainwater management functions. It is conducive to the transformation from the traditional residential planning method to the multi-parameter design method, and achieves the goal of improving the comprehensive benefi ts of the residential green space system. Through simulation experiments, it can be seen that in the form of green space in residential areas, other morphological indicators are kept unchanged, and the larger the green space is, the higher the storage rate of rainwater is, and the stronger the regulation of rainwater runoff is. The morphological characteristicsof green space have different effecton runoff control. According to amount change of rainfall runoff, the influence of morphological characteristics on runoff control is judged. From being strong to weak, green land scale > green space uniformity > green space dispersion > green space shapes index. Complex morphological indices have less effect on rainfall runoff at residential scales. About the residential building layout mode, different settlement patterns are the same for the control of the runoff in the two scenarios of general rainfall and heavy rain. From being strong to weak, the original site > low-level scatter > high-level scatter >group type>multi-level determinant>high-rise peripheral settlement shapes index. Site development will lead to a certain advance in the arrival time of the runoff peak. It can be seen from the simulation results that the peak arrival time of the same settlement mode is closer in the normal rainfall and heavy rain scenarios.The peak arrival time of different runoff patterns is different, from being early to late, the elevation periphery = elevation scatter = group = multi-level determinant