Based on the modified nonlinear Schrdinger equation, the evolution equations for parameters of super-Gaussian pulse with different factor of sharpness was derived under the influence of dispersion(the second-order and high-order) and nonlinearity (the third-order and quintic) by using variational method, and the evolution equations were calculated by using Runge-Kutta algorithm. The numerical results indicate that when the coefficients of dispersion and nonlinearity are small, there always exist coefficients of the third-order and the quintic nonlinearity that can compensate the influence of broadening on super-Gaussian pulse caused by the second-order and high-order dispersion effectively, in this case, the super-Gaussian pulse can transmit conformally. When the ratio of dispersion and nonlinearity is too big, the pulse is broadened infinitely.