A positioning error correction method, suitable for correcting a positioning error of a three-dimensional laser processing apparatus, the method being characterized in comprising: (a) making a laser beam focused on a three-dimensional working area through a zoom lens set and a scanning mirror module sequentially, wherein the three-dimensional working area has a plurality of reference planes (RF1, RF2, RF3), and the reference planes (RF1, RF2, RF3) are perpendicular to a first direction; (b) adjusting a first parameter of the zoom lens set for one of the reference planes (RF1, RF2, RF3), such that the laser beam is correspondingly focused on the one of the reference planes (RF1, RF2, RF3); (c) recording the first parameters respectively corresponding to the one of the reference planes (RF1, RF2, RF3) to create a laser offset compensation table; (d) providing a correction test piece and moving the correction test piece to the one of the reference planes (RF1, RF2, RF3), wherein the correction test piece has a correction pattern; (e) loading the laser offset compensation table and correspondingly adjusting a plurality of second parameters of the scanning mirror module, such that a plurality of correction points (A0-A8) of the correction pattern are separately and correspondingly focused and imaged on a center of a visible area of an image detector through the zoom lens set and an imaging lens set; (f) recording the second parameters to create a visual distortion compensation table; (g) providing a processing test piece and disposing the processing test piece on the one of the reference planes (RF1, RF2, RF3); (h) loading the laser offset compensation table and reading the first parameter corresponding to the reference plane, so as to process and form an alignment pattern; (i) loading the visual distortion compensation table and correspondingly adjusting a plurality of third parameters of the scanning mirror module, such that a plurality of alignment points (W0-W8) of the alignment pattern are separately and correspondingly focused and imaged on the center of the visible area of the image detector through the zoom lens set and the imaging lens set; and (j) recording the third parameters to create a laser distortion compensation table. (a) making a laser beam focused on a three-dimensional working area through a zoom lens set and a scanning mirror module sequentially, wherein the three-dimensional working area has a plurality of reference planes (RF1, RF2, RF3), and the reference planes (RF1, RF2, RF3) are perpendicular to a first direction; (b) adjusting a first parameter of the zoom lens set for one of the reference planes (RF1, RF2, RF3), such that the laser beam is correspondingly focused on the one of the reference planes (RF1, RF2, RF3); (c) recording the first parameters respectively corresponding to the one of the reference planes (RF1, RF2, RF3) to create a laser offset compensation table; (d) providing a correction test piece and moving the correction test piece to the one of the reference planes (RF1, RF2, RF3), wherein the correction test piece has a correction pattern; (e) loading the laser offset compensation table and correspondingly adjusting a plurality of second parameters of the scanning mirror module, such that a plurality of correction points (A0-A8) of the correction pattern are separately and correspondingly focused and imaged on a center of a visible area of an image detector through the zoom lens set and an imaging lens set; (f) recording the second parameters to create a visual distortion compensation table; (g) providing a processing test piece and disposing the processing test piece on the one of the reference planes (RF1, RF2, RF3); (h) loading the laser offset compensation table and reading the first parameter corresponding to the reference plane, so as to process and form an alignment pattern; (i) loading the visual distortion compensation table and correspondingly adjusting a plurality of third parameters of the scanning mirror module, such that a plurality of alignment points (W0-W8) of the alignment pattern are separately and correspondingly focused and imaged on the center of the visible area of the image detector through the zoom lens set and the imaging lens set; and (j) recording the third parameters to create a laser distortion compensation table.