In order to understand the dynamic performance of stacking robot more comprehensively and analyze the influence of arm deformation on the motion accuracy of stacking robot. Taking ABB IRB760 robot as the analysis object, the rigid-flexible coupling dynamics model was obtained by Lagrange method. Then, ADAMS software was used to conduct rigid-body dynamics simulation and rigid-flexible coupling dynamics simulation for the robot's movement process in a working cycle. The velocity curve of flexible simulation of robot end-effector was basically the same as that of rigid simulation, and the velocity changes in the running process were stable and continuous without abrupt change. However, the displacement curve was different when the robot's running state changes, and the acceleration of flexible simulation fluctuated greatly. The flexible deformation of the stacking robot arm has a great influence on the operation accuracy and stability of the robot, the rigid and flexible coupling method can be used to analyze the operation state of stacking robot more accurately.