The impingement of muzzle blast wave is an important engineering problem and has been widely discussed for decades. The problem becomes more complex when the cannon shots at a high frequency. An accumulation phenomenon of the impingement of multiple blast waves is observed. In this research, the numerical study on impinging flows, which are generated by the propellant gas released from the muzzle of a high-frequency launch system, is achieved. The interior ballistics model is employed in the simulation of muzzle flow. In order to have insight into the effect of continuous impingement, three cases with different launch frequencies are studied and compared. Under the computational load of muzzle flow impingement, the dynamic response of monitoring equipment is discussed based on an elastic mechanics model, and the contribution of the impinging frequency to the damaging effect is analyzed. It can be concluded that the frequency of the muzzle flow impingement has an important influence on the damaging effect. Furthermore, the accumulation of impingement depends on the shooting frequency and the intensity of each impingement.