Groove milling clamp for machining key groove center and aligning tooth center and using method

The invention relates to the field of machining technologies, in particular to a groove milling clamp for machining a key groove with the center aligned with the tooth center and a use method of the groove milling clamp for machining the key groove with the center aligned with the tooth center. The two axial ends of each station are each provided with a V-shaped block used for containing a to-be-machined part and a pressing unit used for pressing the to-be-machined part on the V-shaped block, a tooth groove positioning unit and a tooth groove inspection unit are arranged in each station, the tooth groove positioning unit is located below one outer tooth and used for positioning a tooth groove according to a hobbing mark, and the tooth groove inspection unit is located below the other outer tooth and used for inspecting the tooth groove according to the hobbing mark. The tooth groove inspection unit is positioned above the other outer tooth and is used for inspecting whether a hobbing mark is correct or not; t