In response to the need for improvement of the new three-stage piston pusher centrifuge such as the gradual increase in production capacity, the diversification of raw materials and the optimization of the centrifuge structure, the vital influence of operating parameters on the erosion phenomenon and separation efficiency in the drum during the separation process has been confirmed. The simulation software's pre-processing parameters were concluded based on the raw materials' experimental sampling and the corresponding piston pusher centrifuge provided by the manufacturer, starting from the material's particle size. The three-stage piston pusher centrifuge was modeled in three dimensions, using discrete phase and continuous phase. The solid-liquid separation process was simulated by the combined method and the dense discrete particle model (DDPM) was used to simulate the erosion process. Finally, the data was analyzed in combination with experiments to obtain the size and rules of the erosion of each structure by the particles during the separation process and the new equipment's optimal operating parameters. It was concluded that when the particle size dm of sodium chloride particles was between 0.070 mm and 0.200 mm, as the particle size increased, the solid phase's erosion inside the centrifuge drum became greater. Using prototype experiments and CFD numerical simulation combined with response surface analysis, the interactive influence of each factor of the response model was evident. The influencing factors from high to low were drum's rotating speed, feed concentration, and push frequency for the separation rate. For the erosion rate, the influencing factors from high to low were the drum's rotating speed and the feed concentration. Considering higher separation rate and lower erosion rate as evaluation indicators, the optimal value obtained as push frequency of 40 times/min, drum's rotating speed of 1431 r/min, and feed concentration of 60%. Compared with the experimental data, the simulation error was within the acceptable range.