Due to the existence of the two rotation axes, actual tool path obtained by interpolation deviates from theory programming line, resulting in a great nonlinear error. Through the study of kinematics analysis of coordinate transformation, the principle of tool motion and interpolation of fiveaxis machine tool with double pendulum head, the causes of nonlinear error were obtained.A interpolation algorithm based on time division method was introduced. The simulation experiment and parameter analysis based on MATLAB were carried out. The results show that the algorithm is effective.