Significant radiometric differences and weak grayscale correlations exist between optical and SAR images. As a result, there are severe spectral and spatial distortions in the fused images. We propose a fusion method of optical and SAR remote sensing images that couples the gain injection method and the guided filter. The proposed method is based on the fusion framework of generalized intensity-hue-saturation non-subsampled contourlet transform, and the gain injection is used for the low-frequency coefficient fusion to reduce the spectral distortion. Then, the divergence is used as the activity measure operator to calculate the initial weight template for the high-frequency coefficients. The guided filter is used to optimize the edge details of the initial weight template. The fused high-frequency coefficients are obtained by weighted average. Through comparison experiments with existing fusion methods, the results show that the proposed method has the best quality of fusion and the proposed method has the best performance.