Workpiece assembling jig and assembling method

The invention relates to the technical field of workpiece assembling, in particular to a workpiece assembling jig and an assembling method. The workpiece assembling jig is used for assembling a first workpiece, a second workpiece and a third workpiece, and comprises a base, a first clamping device and a second clamping device, the bearing mechanism is arranged on the base and used for positioning the first workpiece; the feeding mechanism is used for clamping a second workpiece, and the feeding mechanism is in sliding connection with the base so as to convey the second workpiece to be in matched butt joint with the first workpiece; and the press-fitting mechanism is used for mounting a third workpiece and pressing the third workpiece into the butt joint of the first workpiece and the second workpiece, so that the first workpiece and the second workpiece are connected through the third workpiece. Through cooperation of the bearing mechanism, the feeding mechanism and the press-fitting mechanism, coaxial assemb