In order to establish a model of aircraft engine blade repair welding machine which could reflect the real motion for more,then improve the dynamic stability of the machine,multivariate factor dynamics analysis was done for axis motion of aircraft engine blade repair welding machine according to kinetic theory.Synthesis dynamics analysis for the motor,bearings,screw,screw vice and workbench was made.Associating the axial displacement with axial force and torque through the dynamic stiffness,modeling and simulation were done.Comparing the simulation results with the results got after modifying parameters and the results got using other model,it is shown that dynamic stability and sensitivity of the model are more excellent.