The utility model relates to a machining clamp of through hole parts. The machining clamp of the through hole parts comprises a central spindle, a locating sleeve and a nut, wherein the central spindle comprises a basic standard outer circle section and a thread section, the locating sleeve is installed between the basic standard outer circle section and the thread section of the central spindle in a sleeved mode, and the nut and the thread section of the central spindle are connected in a thread-screw fit mode. The machining clamp of the through hole parts is simple in structure and easy to operate, can not cause deformation of thin-wall parts, ensures that locating accuracy of parts is accurate, improves coaxiality of all positions of the parts, solves the problems of coaxial accuracy errors of the parts in a machining process, and improves machining accuracy.