Research on a servo tracking system mounted with a small arm for robot fighting platform based on multi-body system dynamics and intelligent control theory is presented. A multi-body dynamic model which can accurately express dynamic performances of the system is built in ADAMS. In addition, an intelligent PID control model is built with MATLAB/Simulink, and the two models are integrated and co-simulated by the interface of ADAMS/Controls. Simulation experiments indicate that co-simulation technique used for design of the servo tracking system mounted with a small arm can effectively improve its design efficiency, and can also provide theoretical bases for the motion control and performance improvement of the servo tracking system mounted with a small arm.