The perturbation method is applied to the multi-order exact solutions of nonline ar evolution equations. The exact solutions to the zeroth-order equation can be derived by Jacobi elliptic function expansion method, and then the first-order a nd the second-order equations can be rewritten as the homogeneous Lam equa tion and inhomogeneous Lam equation, respectively. They can be solved by using Lam functions and the Jacobi elliptic function expansion method. Thus, the mu lti-order solutions are obtained to the nonlinear evolution equations.