The invention provides a welding calibration method and system based on image recognition. The welding calibration method comprises the following steps of acquiring a pixel offset value between a position of a battery module in a captured image and a preset datum point of a battery module; calculating an obtained actual offset between the position of the battery module and the datum point of the battery module according to the pixel offset value and a pixel ratio of a camera; and moving the battery module to the corresponding welding pressure point for laser welding through moving of an A/B axis according to the actual offset. According to the welding calibration method and system based on image recognition, the welding pressure point of the battery module in a five-axis welding system can be accurately calibrated so that the accurate welding pressure point can be obtained, and the battery module can be welded accurately.