Abstract: Yixing City, Jiangsu Province, located in the major passage of upstream flood from western area into the Taihu Lake, is threatened with great flood control pressure in flood season.In order to solve the flood problems in its urban areas, this paper studies an optimal scheme of combination of control and discharge to properly deal with the upstream flood, local flood and southern mountain torrent by using one-dimensional river network model on the premise of not affecting regional flood discharge.Based on the analysis of peak-arriving time and encounter opportunity of external flood, mountain flood and local waterlogging, a reasonable drainage scale of the urban area is calculated and routed.The results show that:(1) After the formation of the urban planning pattern in Yixing City, in case of a 50-year designed rainstorm, 56% of the upstream flood volume will be detoured around the city, 44% still enter the city but is pumped out of the city.And according to the planning, the maximum flood level will drop by 88 cm through the newly added pumping station with 350 m3/s pumping and drainage flow, so the regional flood discharge and urban flood control and drainage will be guaranteed.(2) Controlling periods of flood peaks from different areas are diverse.In general, regional flood lasts for 7～15 days, local flood lasts for 24 hours, and mountain flood lasts for 6 hours.The reasonable combination of the three peak values should be fully considered in determining the scale of the drainage pump stations to avoid cost waste in engineering construction.The research results can be used as a reference for the study of flood control schemes in urban areas with similar flood and waterlogging conditions.