Grinding method of combined edge finishing broach for broaching fir-shaped mortise

The invention discloses a grinding method of a combined edge finishing broach for broaching fir-shaped mortises, which comprises the following steps of: respectively machining a front angle, a side contour and a rear angle of a broach to be machined through a first grinding wheel, a second grinding wheel and a third grinding wheel to form a molded surface cutting part; and then five continuous cutting teeth at the tail of any side of the molded surface cutting part are gradually machined through a fourth grinding wheel, a fifth grinding wheel and a sixth grinding wheel, and a first tooth top cutting tooth, a second tooth top cutting tooth and a tooth top shape correction tooth are formed. Due to the fact that the molded surface cutting teeth, the first tooth top cutting teeth, the second tooth top cutting teeth and the tooth top shape correcting teeth of the combined-edge finish broaching tool are integrally machined, the machining precision can be guaranteed to be consistent, and therefore the phenomenon tha