This article does research on 4MSC-3000 cotton picker transmission system thorough. It establishes transmission system dynamics model and vibration differential equation, ADAMS virtual prototyping technology is used to do simulation on the transmission system. Kinematics relations and dynamic characteristics of the transmission system are found out. Through the dynamic analysis of the model to solve, we can get kinetic curve of gearbox, each axis, gears and so on. Then provide the necessary theoretical basis for follow-up prototype design.