<正> A simulated annealing based coefficient optimization approach to improve the image fusion performance is proposed in this article. Image fusion is a process of combining multiple images into one that describes the actual scene more accurately than any of the individual inputs. However, assessing the fusion performance mdming the performance measurement so improve the fusion result are still open for discussion. This article tries to answer two questions. Firstly, reference images used in most previous literature to measure the performance of fusion process are often real scene image or the equivalence, which hardly exists in practice. To avoid using the nonexistent real scene image, an alternative reference is created through extracting and merging edge features from each input image. Secondly, the performance measurement needs to be involved in optitmuzation process. Our method adopts a simulated annealing procedure to optimize the Wavelet coefficients combination. As the objective function, the cumulative edge distance is minimized by adjusting the magnitude of the wavelet coefficents according the error matrix, so as to approaching the optimal coefficient combination.