Non-tenon-end bending finish forge blade longitudinal detecting datum determination method

The invention relates to an improvement on a non-tenon-end bending finish forge blade longitudinal detecting datum determination method, and belongs to an aero-engine blade forging technique. The datum comprises a first positioning point K1, a second first positioning point K2, a third positioning point K3, a fourth positioning point M1 and a fifth positioning point M2 of a blade body (2), and is characterized in that a sixth positioning point is one of the following two points: (1), the sixth positioning point S1 is the center of a sphere of a quarter sphere at the right end of a blade root positioning boss (1), and (2), the sixth positioning point S2 is the center of the sphere of a quarter sphere at the left end of a blade tip positioning boss (3). With the non-tenon-end bending finish forge blade longitudinal detecting datum determination method, influence on the detection datum caused by change of size of blade tip positioning boss end face is avoided, and accuracy of testing results is guaranteed.