Abstract: Aiming at the arc-drawing problem of rail gun armature at muzzle exit, a muzzle arc suppression scheme based on shunt is proposed in this paper. Taking solid armature as the research object, the simulation model of electromagnetic rail launching system with arc suppression device is established by using Simulink software. The purpose is to achieve the best match between the electrical parameters of the arc suppression device and the electrical parameters of the launch system through the simulation calculation of the different impedance values of the arc suppression device, so as to reduce the influence of the arc suppression branch on the speed of the armature outlet, and at the same time effectively restrain the arc of the muzzle. By optimizing the parameters of resistance and inductance of the arc suppression device, the impedance of the arc suppression branch is far greater than that of the armature branch in bore, and the launch current mostly flows through the armature, which has the least effect on the armature speed. After the armature is out of the muzzle, the impedance of the arc suppression branch is less than that of the arc, thus a reasonable arc rapid elimination is established. The residual energy of the launching system can be released by the arc suppression device to reduce the influence of the muzzle arcing on the launching performance. After the calculation and analysis of the multi parameter values of the resistance and the inductance of the arc suppression device, it is determined that the arc suppression resistance matching the transmission system in this paper is about 1 mΩ, and the inductance is about 1 μH. Combined with the structure of the launching device, the resistance and inductance of the arc suppression device are 1.32 mΩ and 0.124 μH respectively. In the simulation model of the launching system, the launching simulation calculation of the charging voltage 3 kV is carried out. Under the energy level of the charging voltage 3 kV, the arc suppression launching test is carried out. The simulation results are in good agreement with the test results, and the arc suppression effect is good.