During the laser (single) triangulation measurement, the measurement error of the surface profile height is caused by the deflection of projecting beam axis or the reflected spot center offset of projecting beam shining on object surface with nonuniform reflectivity. A method is introduced to amend the deflection of projecting beam axis and the reflected spot center offset of projecting beam by using dual- triangulation light path, and a modifier formula is deduced. It is proved to be right through the profile height measurement on the reflectivity mutation position of the object surface. According to dual- triangulation measurement of the grayscale stripe template profile, the root mean square deviation of the profile height is less than 0.07 mm.