To ensure the fusion quality and efficiency simultaneously， a novel image fusion method based on multi-scale Gaussian filtering and morphological transform is proposed. The multi-scale Gaussian filtering is designed to decompose the source images into a series of detail images and approximation images. The multi-scale top- and bottom-hat decompositions are used respectively to fully extract the bright and dark details of different scales in each approximation image. The multi-scale morphological inner- and outer-boundary decompositions are constructed to fully extract boundary information in each detail image. Experimental results demonstrate that the proposed method is comparable to or even better in comparison with typical multi-scale decomposition-based fusion methods. Additionally， the method operates much faster than some advanced multi-scale decomposition-based methods like NSCT and NSST.