Aiming to meet its operational challenges, the parameters of a wheat flour equalpitch screw feeder are mainly based on empirical design, but systematic research of its optimization is lacking. Thus, an optimization method was presented based on particle swarm optimization. Firstly, to improve the accuracy and rationality of the algorithm optimization results, the large error between the empirical calculation formula of the mass flow rate was mitigated, and actual tests were done. The differences between the response value, pitch S, inner shaft diameter d, and rotational speed n, which had significant influences on the flow difference, were taken as variables. The orthogonal experiments were designed by using DesignExpert software, a secondorder regression equation between the three variables and the response value was established and the modified formula of wheat mass flow rate was obtained. Then, according to the modified formula, based on particle swarm optimization, with maximum mass flow rate and smallest screw weight as the optimization goals, the outer diameter of the blade, pitch, outer diameter of the inner shaft, and inner diameter of the inner shaft were taken as variables. The two goals were then transformed into singleobjective optimization problems in a proportional way for optimization. Finally, tests were carried out according to the optimization results, showing that the optimized mass flow rate was 3.0546t/h, which was 18.15% higher than the empirical design value of 2.5853t/h, and the screw weight was 6.2779kg, which was 29.39% lower than its empirical design. The theoretical mass flow rate of the modified optimization result was 2.8647t/h and the error for the actual measured flow value of 3.0546t/h was 622%. The result demonstrated the reliability of the modified mass flow rate calculation formula and optimization design method, which provided a reference for the design of a wheat flour equalpitch screw. 