Abstract:Muzzle brake plays a crucial role in gun design, it can effectively reduce the recoil of the gun. But the negative effect is that the muzzle shock wave causes overpressure and overtemperature in the gunner''s area. In this paper, the numerical simulation of muzzle flow field was carried out by FLUENT software, and the influencing factors of brake performance were simulated and analyzed, and the rules were obtained. According to the analysis results, the improved brake model was obtained, and the simulation was compared. The results showed that the performance of the brake was most affected by the side hole external reflection baffle and the side hole inclination. The overpressure and temperature behind the muzzle were reduced effectively by installing the blow hole. The efficiency of the improved brake was increased by 8.33%, the overpressure behind the muzzle was decreased by 44.099kPa on average, and the temperature behind the muzzle was decreased by 358.284K on average. It was proved that the improved brake has higher efficiency and lower overpressure value and temperature value behind the muzzle. The method used in the analysis process and the conclusion obtained have certain guiding significance for the research of brake.