Motor rotor measure ruler

The utility model relates to a motor rotor measuring tool and specifically relates to a motor rotor measure ruler which includes a tabular ruler body. A ruler surface at one side of the ruler body is an arc surface and the arc surface fits a radian of an arc surface of the outer surface of a to-be-tested motor rotor. A reference point is arranged on the ruler body at one of ruler edges which have directions identical with the circumferential surface direction of the rotor, and a size scale mark is arranged on the other ruler edge. The measure ruler, the ruler surface of which is an arc surface, is adopted and the arc surface of the measure ruler can fit the radian of the arc surface of the outer surface of the to-be-tested motor rotor; and the scale and the reference point are arranged on the measure ruler and according to the measurement numbers of the measure ruler, and a geometric similarity relation, a skewed slot angle of the rotor can be rapidly obtained so as to judge whether a product is up to standard.