The invention discloses a workpiece axis positioning error compensation method for an axle housing roundness and cylindricity detecting device and belongs to the field of detection. The method is characterized in that an axle housing positioning model is built, a first section, a second section and a third section are arranged on the model, and the second section and the third section are used tocorrect the first section step by step. The method specifically includes: a target section uses O as the benchmark to perform spatial translation on a circle contour where O1 is located, performing axis eccentricity compensation to obtain a section S1 after eccentricity correction, and an axis L and the section S1 are rotated a theta degree along a Z axis to obtain a section S2; the axis L and thesection S2 are rotated an alpha degree along a Y axis to allow the axis L to coincide with the Z axis so as to obtain a section S3; the section S3 and the axis L are reversely rotated theta degrees to obtain the section S4; error evaluation is performed on the section S4 to obtain real roundness errors with workpiece axis positioning eccentricity inclination errors being removed, and a constraintcondition beta is provided. The workpiece axis positioning error compensation method can compensate roundness errors and cylindricity errors caused by workpiece axis positioning eccentricity and workpiece axis positioning inclination, increase axle housing detection precision and meet ultra-precision machining requirements.