The invention discloses a device and method for automatically checking the appearance of an electronic system extension product, and the device comprises a transferring supporting plate, a multi-angle indexing table, a transferring track, a protective cover, a visual photographing assembly, a multi-axis robot, a transferring disc and a main control computer. The transferring supporting plate is used for installing the extension product, and is installed on the multi-angle indexing table; the multi-angle indexing table is mounted on the transferring disc capable of moving on a transferring track, the extension product is fed into an inspection area through the transferring disc and the transferring track, and the protective cover is arranged in the inspection area; in the inspection area, the multi-axis robot with the visual photographing assembly arrives at different photographing points, so that the photographing of the extension product in different postures, visual angles, distances and areas is achieved, and the photo files are stored; the main control computer is connected with the multi-axis robot, controls the operation of the multi-axis robot and is used for man-machine interaction and the like. According to the invention, the inspection result is more objective and efficient, the efficiency and accuracy of the appearance inspection work of the electronic system extension product are improved, and the appearance quality of the product is ensured.