Abstract: To achieve optimal design of a perforated water distribution system, this paper proposes a particle swarm optimization (PSO) algorithm combined with hydraulic modeling tools as a systematic approach to decision making. First, the algorithm improved the standard PSO to enhance the convergence rate and the capability of global convergence. Then, with the external TOOKKIT interface, a combination of the improved PSO with hydraulic models had been developed for fitness evaluation. The case study shows that this method is capable of realizing optimization of the design program with certain limited conditions. Meanwhile, a scheme corresponding to engineering practice can be developed with the strategy of node pressure grouped, and the approach reduces the particle dimensions and speeds up the convergence rate about 83%.