Battery pack appearance detection method, device and system

A battery pack appearance detection method, device and system, applied to the technical field of computer vision, the detection device comprising: an image acquisition unit for acquiring an image of a first battery pack to be detected, the image presenting a part or all of the outer surface of the first battery pack; the processing unit is used for inputting the image into a detection model corresponding to the second battery pack so as to obtain a detection result for the first battery pack; wherein the similarity between the appearances of the first battery pack and the second battery pack is greater than or equal to a similarity threshold value, and the detection model corresponding to the second battery pack is used for detecting the first type of defects; the first detection result comprises at least one of the following items: indicating whether the first defect exists on the outer surface of the first battery pack or not, and indicating the position of the first defect on the outer surface of the first