The invention discloses a gantry crane grab bucket path optimization method and belongs to the technical field of crane control. According to the gantry crane grab bucket path optimization method, after the movement starting point and the movement terminal point of a grab bucket are determined, a projection point, vertically projected on a connection line between the starting point and the terminal point, of a rotation center point of a gantry crane is found out; the grab bucket is firstly moved to the projection point from the starting point and then is moved to the terminal point; and therefore the grab bucket can move to the terminal point from the starting point along a horizontal straight line, the grab bucket movement path is optimized, it is guaranteed that when being started, the gantry crane is free of waggling and cannot lurch on one side, and the problem that because of site limitation, a rotating mechanism cannot substantially rotate is more effectively solved.