[Objective] The objective of this thesis was to explore the spatial distribution of different cities and analyze how layout indexes, such as water flow length, and area ratio of both green space and buildings affect the runoff outlets. It was for the purpose of optimizing the spatial layout of urban typical bottom cushion and realizing the control of urban rainwater runoff.[Methods] Taking the central zone of Luohe City as the research object, based on the aerial image in March 2016, extracted the land cover information of the central urban area, and used the SWMM to analyze the runoff characteristics in different rainfall recurrence periods and to extract the factors affecting the rainfall runoff. At the same time, the influences of urban buildings and green spaces to runoff reduction and layout were also studied.[Results] There was a significantly negative correlation between the runoff coefficient and the values of green space and the construction area ratio. Additionally, the flow length of the water outlet had a significant effect on the runoff effect. The runoff coefficient of subcatchment was smaller which green space near the outlet was smaller than buildings, and it was found that the rate of runoff reduction got up to 44.49% when the recurrence period was 5 a.[Conclusion] Through reasonable arrangement of scale and layout of green space and construction in combination with factors as water flow length and area ratio, rainwater space redistribution can be realized, runoff reduction can be achieved.