Abstract: To make sure that the fused multispectral image keeps greatly the spectral characteristics of the original multispectral(MS) image and most likely to improve the spatial resolution,this paper introduces the technology of Gaussian scale space that can simulate the mechanism of human visual and proposes a spatial projection method based on Gaussian image cube.The proposed method can improve the spatial resolution of the fused MS image effectively,while it can make little spectrum distortion to the fused images.The experimental results of fusing QuickBird remote sensing images show that,comparing to traditional methods,the method proposed in this paper has a distinct advantage in subjective visual experience,spectral deviation,correlation coefficient,UIQI,ERGAS and Run-time indicators.