The dynamic coupling simulation of urban water supply network and non-negative pressure water supply is very important for the security of urban water supply. The three related aspects were studied in the paper. Firstly, taking an independent area of city K water supply system as an example, the coupling hydraulic modelling was built based on EPANET software. Then the nodes of residential water consumption in the network were installed with non-negative pressure equipment ergodically. Therefore, the suitable node locations for installation were obtained, and the sensitive nodes in the pipeline network were listed at the same time. Lastly, for the simultaneous multi-point utilizations of non-negative pressure equipment, the operating situation was simulated and the impact on the pressure of the municipal pipeline network was analysed. Based on the hydraulic simulation results and genetic algorithm, the layout of secondary water supply with non-negative pressure was optimized. The theory on non-negative equipment proposed in the paper is also applicative for other cities.