River desertification is increasingly prominent in the plain of West Liaohe river. A series of ecological environment problems have been triggered, water resources shortage is the main cause of the river desertification. A planning model of water resources management within the plain of West Liaohe River was established with the MIKE BASIN software. The model was validated in three aspects including runoff, water supply and water storage variation of the watershed key nodes according to the characteristics of water cycle in plain area, the results were satisfactory. The supply and demand status of water resources in the 2020 level year of the study area was analyzed using the established models based on water resources three- time allocation theory. The results showed that, the water shortage degree was 24.7% in the plain of West Liaohe River, which belonged to resource shortage. Strengthening water saving and inter-basin water transfer were effective measures to solve the contradiction between water resources supply and demand in this area. Water demand was reduced by 63.6% after taking the strengthening water saving measure. After the inter basin water transfer project of water regulation from Chuo river to West Liaohe river is implemented, water shortage problems can be alleviated in the water receiving area and the groundwater level is expected to rise 0.16m every year in Horqin district of Tongliao City.