Improving the launch efficiency of multi-stage synchronous induction coil gun is one of the hotspots in coil launch research. n this paper, the electromagnetic force is solved based on the equivalent circuit model and the virtual displacement method. The 140 kg armature driven by the five-stage coil is taken as the research object. The finite element software Ansys Maxwell is used to establish and optimize the multi-stage coil emission model. The simulation analysis is completed by considering the AC skin effect of the coil and the eddy current loss of each metal component, and the five-stage coil emission experimental platform is built to verify the accuracy of the model. The main conclusions are as follows: Under the same conditions, the speed difference between simulation and experiment is only 2.9%; at 4.8 kV of single-stage coil, the experimental speed of 140 kg armature driven by five-stage coil is 49.1 m/s, and the emission efficiency is 18.3%.