The four axis linkage system is mainly composed of XY galvanometer, XY motion platform, platform driver, GMC control card and general marking software. It has the function of unlimited field of vision and can synchronize linear servo axis and laser scanning galvanometer. When the high dynamic performance of the scanning galvanometer is combined with the large travel range of the servo platform, it can continuously process a larger working range than the traditional galvanometer, without splicing the working area. The four axis linkage system not only expands the working range of the scanning galvanometer system and the application range of a single optical device, but also avoids the interaction between the laser beam range and the available working range, and improves the processing quality and the production of large parts.