The small parameter perturbation approximation is applied quite often in applied mathematics and mechanics. There are tremendous conservative system analyses in physics and applied mechanics, and one of the most important characteristics of a conservative system is its symplectic conservation. The present paper emphasizes that the symplectic conservative behavior should be considered in small parameter perturbation approximations. The strip domain structural analysis is considered, and we gave both the perturbation solutions with the displacement method, which is symplectic conservative, and the perturbation solutions with the corresponding transfer symplectic matrix method, which is symplectic nonconservative.