The invention discloses a wire-width-variable laser galvanometer scanning quick etching method and device. The principle that after laser beam is defocused, the power density gradient becomes small, and a light spot becomes large is used, a high-speed galvanometer scanning error accurate correcting method is used, by setting different focusing and defocusing laser processing distances and corresponding power parameters and laser galvanometer scanning parameters, the size of the laser light spot is controlled, large light spot raster scanning filling after defocusing is carried out is on an image filling zone, and then an image contour is subjected to vector scanning drawing. For different working distances, galvanometer scanning error correcting is carried out first, a high-accuracy galvanometer scanning locating table is formed, and the fact that the same high-accuracy galvanometer scanning locating effect is obtained at different laser processing distances is guaranteed. Quick accurate etching on images with different wire widths can be achieved, etching accuracy and processing speed are considered at the same time, the method and device can be widely used a plane etching system and a three-dimensional laser etching system, and the processing efficiency of equipment is improved.