Abstract: Recently rainwater-collection-storage-utilization(RCSU) has been one of effective measures to explort additional water resources in the water-lacking hilly areas. It is the basic approach to accelerate the development of agriculture economy, and for the peasants to eliminate the poverty and become rich, but the theoretical analysis needs discussing and perfecting further. According to the rainwater utilization programming in the hilly areas in Xinyi city, this paper puts forward a self-optimization simulation model that is applied to the optimal regulation analysis of RCSU. The analysis of the calculation results shows that the selected method and the model are feasible and effective in practice, and the optimal regulation processes of irrigation on RCSU are realized.