The ram air turbine (RAT) acts as an emergency energy source on the aircraft and provides electrical energy in the event of an emergency to ensure the on-board transmission control and the normal operation of the electronic equipment. The ram air turbine is taken as the research object, and the system model is simplified based on the principle of mechanical motion. The kinematics problem of the structure in the release process is theoretically studied using MATLAB. The theoretical solution method for the spatial position of each joint in the RAT system release process is given. The motion trajectory of the joint in space and the corresponding velocity time curve and acceleration time curve are obtained. The results show that the release process of the RAT system is within 1 s. The release speed is fast, and the speed and acceleration response of each joint in the initial stage of release are quite large. This work can provide theoretical basis for the preliminary design of different RAT system configurations in the later stage, and guide the simulation calculation and experiment of RAT release.