Abstract： The problem of dynamic optimization of urban domestic water input was studied to optimally adapt to the changes of urban population under the process of urbanization. The product of logistic equation and per capita water demand was used to denote domestic water demand, and CD production function was used to denote water supply. Through the dynamic coordination of capital and labor input, the urban water supply dynamic was made to meet domestic water demand, realizing dynamic optimal configuration of water supply input. The system simulation show that expanding the scope of the value of capital and labor input can accelerate up the narrow urban domestic water supply and demand balance and achieve equilibrium.