The work aims to propose an algorithm to enhance the weak visible light image based on Retinex and then to fuse image based on NSST and SWT for the problem that the images after the fusion of weak visible light and infrared images still have a large amount of details lost and blurred target. Firstly, the SSR was used to enhance the low visible light image, and then the enhanced visible and infrared images were decomposed by NSST to obtain the first high and low frequency coefficients. The high frequency coefficients were fused by a method based on local energy characteristics. The low frequency coefficients were decomposed by SWT to obtain the second high and low frequency coefficients. The high frequency coefficients of the second time were fused by the same method, and the low frequency coefficients were fused by the linear weighting method. Then, the low frequency coefficients of the second time were obtained through the inverse transformation of SWT. Finally, the fusion results of the high frequency coefficients of the first time and the new low frequency coefficients were transformed by NSST inverse transformation to obtain the fusion image. Through simulation experiments, the proposed algorithm was compared with NSST, NSCT, and the algorithm in literature 5. The results showed that the fusion image details were clearer in subjective vision, and the average gradient, standard deviation, information entropy and information retention indexes increased by 35.63%, 26.73%, 16.89%, 7.2% and 4.6% respectively in the objective. The proposed algorithm has a better effect on image fusion, and the visibility and quality of the fusion image are improved.