Aiming at the defect of low recognition degree of single sensor to recognize gas leakage fault imaging of GIS equipment, an image fusion method based on Gaussian filter-VGG19 is proposed. First, image alignment is performed in the preprocessing stage of infrared and visible images, and then the aligned images are decomposed into low-rank base layer and significant detail layer using Gaussian filtering; second, the low-rank base layer images are processed using Weighted Mean Method to form the fusion base layer, and for the significant detail layer images, a VGG19 network is introduced to extract the multi-layer feature sub-images, and then the multi-layer fusion strategy is aggregated to obtain the fusion results of the salient detail layer to form the fusion detail layer; then, the two fused sub-images are combined by the reconstruction and summation strategy to obtain the final complete fused image. The fused image is input into the Yolov5 gas leakage detection model to realize gas leakage state recognition. Simulation experiments verify the effectiveness of the proposed method in recognizing gas leakage in GIS equipment.