In order to ensure the reliability of the ammunition automatic loading system, the simulation of the drug delivery action of the modular drug delivery machine in different states is carried out by establishing a virtual prototype. Creo is used to create a 3D structure model of the modular drug delivery machine. The model is input into Adams to establish the virtual prototype model of the modular drug delivery device. The control model of the modular drug delivery machine is built with the classic PID control algorithm as the core by using Matlab/Simulink simulation platform. The interface is established in Adams and MATLAB for data interaction to complete the joint simulation system establishment and simulation. The results show that the model can meet the needs of actual drug delivery.