The invention discloses a scanning galvanometer type laser welding system which comprises a laser and light path module, a power module, a galvanometer scanning module, a computer control module, a workbench and a cooling module. A laser beam is irradiated to a welded workpiece through the laser and light path module. Adjustment of a welding circuit and pulse width frequency is achieved through the power module. The galvanometer scanning module is used for enabling focused light beams to form uniform scanning patterns on a scanning plane, the computer control module is used for controlling input of all parameters, welding scanning tracks and movement of the workbench, so workpiece fixing and welding temperature control in the welding process are achieved through the workbench and the cooling module. A scanning path is reasonably selected through computer software, so that the laser beam scans and welds more welding spots within the same time, and the overall spot welding speed is increased; besides, the laser beams are reflected and focused through a light path system, scanning distortion is overcome, welding positioning is more accurate, and the welding effect is better.