Alignment method for guaranteeing symmetry degree of dovetail groove pin hole

The invention, which belongs to the technical field of processing of plate type parts of the aero-engine, especially relates to an alignment method for guaranteeing a symmetry degree of a dovetail groove pin hole. A to-be-processed part is installed and clamped at a processing platform; an alignment program of a dovetail groove is compiled and measured; a plane is formed at a bottom plane of a dovetail groove of the to-be-processed part and a cross section of a pin hole at the dovetail groove is constructed along the oblique plane of the dovetail groove at an L-value height to the upper end surface of the part; and on the basis of a technical requirement T dimension, coordinate values of two intersection points are measured at a plane parallel to the bottom plane of the dovetail groove of the to-be-processed part at a certain height, so that a precise coordinate point and a precise vector angle of the pin hole are obtained. The alignment method has advantages of simple and convenient operation, high processin