The invention provides a blade tenon tooth positioning device. The tenon tooth positioning device comprises a base and a plurality of blocking teeth which are arranged on the base at intervals, wherein a first positioning inclined surface and a second positioning inclined surface which are oppositely arranged are respectively arranged on the adjacent first blocking tooth and the second blocking tooth; and an included angle between the first positioning inclined surface and the second positioning inclined surface is matched with a tooth-shaped angle of a to-be-positioned blade tenon tooth. According to the technical scheme adopted by the invention is applied, the blade tenon tooth positioning device can be used for realizing reliable matching between the plurality of the blocking teeth and the blade tenon tooth, good in stability, and has relatively good measuring precision.