Abstract: According to the design requirements, the 22-tooth tooth surface of the output shaft needs to be ground for the output shaft produced by the company. Product trial production stage adopts the grinding process of clamping the outer circle at one end and clamping the top at the other end, There are some unqualified quality problems in actual production ,such as tooth profile inclination deviation （f_Hα）, helix inclination deviation （f_Hβ）, and the unqualified radial runout of gear ring（F_r）. In order to solve these problems, the special fixture was designed through optimizing the process , the clamping mode was changed to the top of both ends. The rusults show that the indexes of f_sα, f_sβ, F_r of product meet the requirements of internal control of customers, Δf_sα decreased by 56.10% , Δf_sβ decreased by 80% , and ΔF_r decreased by 28.30% in the same batch, which ensured the batch production of the products and provided a reference for the grinding process design of similar products.