There are several typical methods for SAR image superresolution, such as spectrum estimation, regularization, basis pursuit and partial differential equation methods. The relationship of these methods was discussed to provide reference for their synthetic application. First, the sameness and difference of different methods in prior utilizing, problem modeling, and parameters estimating were discussed. Second, the application bound of each method and the selection of methods in engineering application was given. Last, several thoughts for synthetic model were given. The simulation results confirm the merit of synthetic method.