The research on simulation of water distribution of fixed spray plate sprinkler was limited. Experiments were conducted to test the droplet velocity and angle of the Nelson D3000 spray plate sprinkler under different working pressures and different nozzle diameters by using droplets photography technology. Empirical relationship was built and jet velocity and angle were related to working pressures and nozzle diameters. Based on this, a three-dimensional numerical model was developed to describe the water-drop trajectories of individual drops after their releases from the nozzle. The model was solved by multistage Runge-Kutta algorithm and output data included droplet size distribution, water distribution, kinetic energy distribution and water evaporation loss of the sprinkler. A custom computer software script was developed by using Eclipse software to implement the method to engineering case study. Hydraulic characteristics of the Nelson D3000 spray plate sprinkler under different working conditions were simulated by using the software. Single sprinkler data were used to calculate the overlapping uniformity of moving sprinkler irrigation system with different spray sprinkler spacings. Results showed that the simulated droplets distribution and water application were correlated well with the experiment data. The relative error between simulated and measured values of Christiansen uniformity was ranged from 0.04%~ 14.77%, and the software can provide technical guidance for optimal design of linear-move sprinkler machines.