Digital ray inspection is carried out by using two robots for the weld of launch vehicle tank. At present, the teaching device is used to select points to generate a collaborative inspection trajectory, and the quality level of the generated inspection trajectory, synchronization and speed can only be clearly generated through actual operation. In order to make the two robots meet the requirements of efficient inspection of the weld of launch vehicle tank, Using the Robotic_Toolbox_v9.8 module of MATLAB, the model of double KUKA KR50 R2500 robot is established, and the coordinate system of each bar of the double robot is established by D-H parameter method, and the working space of the double robot is obtained by Monte Carlo method, so as to determine the rocket tank suitable for testing. The trajectory simulation of the double robot is carried out by master-slave trajectory following. The curve of angle, angular velocity and angular acceleration of each joint is obtained by quintic polynomial, and the correctness and rationality of the established kinematics model of double KUKA KR50 R2500 industrial robot are verified by forward and inverse kinematics. This method provides a verifiable scheme for trajectory planning of X-ray inspection in complex environment, and also provides a verification method and idea for robot selection and placement in scheme design.