The invention discloses special differential shell type elastic clamping tooling for a helical gear, which comprises a differential shell type body, an elastic nut and an elastic sleeve, wherein the differential shell type body is provided with a connecting hole, a handling hole and a positioning hole, the connecting hole is used for directly connecting a main shaft of a grinding machine, the handling hole is used for putting a workpiece into the differential shell type body, and the positioning hole is used for positioning the workpiece; the elastic sleeve is installed in the positioning hole and matched with the positioning hole, the front end of the elastic sleeve extends out of the positioning hole, and the thickness of the elastic sleeve is gradually reduced in the axial direction of the elastic sleeve from the inner part of the differential shell type body to the outer part of the differential shell type body; and the elastic nut is sheathed on the front end of the elastic sleeve and matched with the elastic sleeve through threads. The special differential shell type elastic clamping tooling has the advantages of convenience in use and simple structure, the workpiece is positioned through an outer circle and an end surface, the elastic sleeve is pulled through the elastic nut to clamp the outer circle of the workpiece, so as to process an inner hole of the workpiece, and therefore, the coaxiality of the outer circle and the inner hole of a transfer case gear is better.