The invention discloses a fixing mechanism for gear shaving. The fixing mechanism comprises a mandrel, a wavy expansion sleeve, a gland and a driving device, which are sequentially arranged from left to right in the axial direction, wherein the mandrel comprises a clamping part, a shaft shoulder and a fixing part, which are sequentially distributed from left to right in the axial direction, the clamping part is detachably connected with a machine tool, the shaft shoulder can be used for locating the end face of a gear, the wavy expansion sleeve sleeves the fixing part, the wavy expansion sleeve comprises a deformation expansion part and a bearing part, which are sequentially distributed from left to right in the axial direction, the gland comprises a columnar body and a lug boss located at the outer part of the columnar body, the columnar body is in clearance fit with the inner hole of the bearing part, the lug boss is propped against the outer end face of the bearing part, the axial gap between the columnar body and the right end of the fixing part is larger than the axial deformation of the wavy expansion sleeve, and the driving device can drive the gland to move in the axial direction. The scheme is simple in structure, is easy to operate, can firmly clamp a gear workpiece, is convenient for quick shaving, improves the gear workpiece shaving efficiency and reduces the cost.