The perturbation approximation should be symplectic conservative. The FEM displacement method is naturally symplectic conservative, the mixed energy representation is also shown symplectic conservative. The stiffness matrix, as well as the mixed energy matrix, perturbations based on the Taylor series expansion are all proved symplectic conservative. However, the Taylor series expansion perturbation for the symplectic transfer matrix is not able to reach symplectic conservative. The symplectic conservative perturbation for a transfer symplectic matrix should be based on the canonical transformation method. Although, the perturbation methods of the stiffness matrix, of the mixed energy matrix and of the transfer symplectic matrix multiplicative perturbation are all symplectic conservative, however, they are not identical. Therefore, numerical comparison is given for an example.