The invention relates to a dynamic deformation calculation method for a high-speed heavy-load robot. The method comprises the following steps that according to design features of a robot body, a basecoordinate system is established at the position of a robot base, robot joint coordinate systems are established at joints of the robot, and D-H parameters at the joints are acquired; a kinematics equation of a tail end device is calculated, the tail end position and posture of the robot is acquired, recurrence on angular velocity and angular acceleration are sequentially conducted, recurrence onvelocity and acceleration are sequentially conducted, and the motion state of each connecting rod in the base coordinate system is calculated; and the inertia force and the inertia moment of each connecting rod are solved, a finite element model of the robot is established, and the total dynamic deformation, stress and strain of the robot are solved. According to the method, a kinetic model of therobot is applied to the finite element model, the deformation situation caused by dead weight, loads and all the inertia force and the inertia moments of the robot is analyzed, various influence factors of the deformation of a tail end point are researched, and a basis is provided for modeling design and parameter optimization of the robot.