Aiming at the problem of non-repeatability, long period, high labor cost, and high technical requirements of the artillery launching experiment, this work studies the virtual simulation technology of artillery external ballistics. According to the characteristics of the artillery firing process, it analyzes artillery particle exterior trajectory equation set and establishes the mathematical model of the external ballistic motion process of the projectile. Combining virtual reality technology and Unity3D development engine, 3ds Max is used to build the artillery and projectile solid model, and C# is used as the development language to calculate and control the ballistic motion of the ballistics, and realize the analogue simulation of the artillery launching process. According to the analysis of the simulation data and the firing table, the simulation experiment is not only visually showing the flight state of the artillery launch and projectile, but the deviation is within the acceptable range, which facilitates the research of the external ballistics of the artillery.