The invention discloses a method for overall calibration of a galvanometer type line laser scanning three-dimensional measuring system. First two lenses whose effective focal lengths are f1 and f2 are selected, and a camera is utilized to shoot a plane target and feature point coordinates are extracted, and main point coordinates of an image are calculated according to a varifocal method; then the lens whose focal length is f1 is used as a lens of the system, and for the feature point coordinates on the plane target which are obtained by the lens, intrinsic parameters and extrinsic parameters of the camera are calibrated; next, by changing galvanometer control voltage and driving a one-dimensional translation table to move, line laser stripes in different depth directions and different optical planes are obtained, and through operation of plane fitting and intersecting line obtaining, a transformation relation between a target coordinate system and a world coordinate system is obtained; and finally, coordinates under a system model are all unified to an image pixel coordinate system and the world coordinate system, thereby completing calibration of the whole system. The method has the advantages of simple calibration process, high calibration precision, fast calibration speed and the like.