Abstract: In order to identify the high risk areas and potential risk paths of non-point source pollution of Chagan Lake, four kinds of key source landscapes were constructed with the water quality target as the constraints. Resistance surface was built by eight assessment factors, including altitude, slope, land use, pollution intensity, and distance from residential land, road, railway and water area. The risk areas and risk paths of non-point source pollution were identified. The control measures were constructed. Our results showed that: (1) There were four types of key 'source' landscapes in Chagan Lake catchment area, which were the high load area of non-point source pollution, the area with gradient > 3°, the pollution transmission channel and the lakeside landscape, covering an area of 126.33 km². (2) High risk area of non-point source pollution is the key control area, accounting for 27.10% of the total catchment area, located in Youzi Lake of Qian'an irrigation area, the lakefront areas and surrounding lake areas. The control measures in this area including: the existing cultivated land should increased, the area with higher slope should returned back to wetland or pasture, and pollution degradation facilities should be built. (3) The relatively high risk area of non-point source pollution is the general control area, accounting for 20.23% of the total catchment area. The organic agriculture and ecotourism in this area were encouraged. (4) Vegetation buffer zones should be constructed on the north bank and southeast bank of Chagan Lake, and on both sides of Kuli Lake. 333.41 km ecological degradation channels and 9 ecological wetland nodes in the catchment area should be planned. The results show that the pollution emission intensity is the main threat to non-point source pollution. It is necessary to strengthen the control of Youzi Lake of Qian'an irrigation area on the north bank and southeast bank of Chagan Lake.