The line structured light galvanometer scanning system realizes three-dimensional profile measurement of the measured objects via swinging a mirror, which has the advantages of strong environmental adaptability, fast measurement speed and compact structure. To reduce the difficulty of system installation and improve the universality of calibration method, a calibration idea is proposed to directly establish the relationship between the coefficients of reflected laser plane equation and the swing angle of galvanometer. The general expressions of coefficients of the laser plane and the swing angle of the galvanometer are deduced and obtained by considering the relative position relationship between the components of the system. According to the coefficients of the laser plane equation obtained at the specific swing angles, the undetermined coefficients in the expressions are obtained by the least square method. The experimental results show that maximum relative height deviation of the steps measured by the measurement system calibrated by the proposed method is -0.3029%, and the multi-scale features of complex surface can also be acquired successfully.