In order to deeply study the mechanism of machining accuracy detection for high-grade CNC machine tools,in this paper,Adams and Matlab/Simulink software was used to simulate the movement of S-shaped test piece produced by five-axis CNC machine with AC dual rotary table.Firstly,the mechanical system and control system model of the machine tool were built.Then the 6 input variables and 12 output variables of the mechanical model were docked with the control model established by Simulink through Adams/Control module respectively,and the settings of input and output in the system were completed,and the co-simulation of electromechanical coupling was realized.The simulation results show that the motion of each axis for the five-axis machine tool presents a non-linear change in the machining S-shaped test piece process,which is consistent with the actual engineering experience.