The invention relates to the field of gear processing, and particularly relates to an end tooth processing fixture and a processing method thereof. According to the end tooth processing fixture, the upper semicircle of a clamping block comprises an upper semicircular cavity and an upper bolt hole; the lower semicircle of the clamping block comprises a lower bolt hole, a lower semicircular cavity, fixed bolt holes and a fixed bottom plate, and the lower bolt hole is opposite to the upper bolt hole; a cylindrical clamping part is formed by the upper semicircular cavity and the lower semicircular cavity; the fixed bottom plate is further arranged on the lower part of the lower semicircle of the clamping block, and the fixed bolt holes are formed in the fixed bottom plate; a correction rod comprises triangular chamfers, chamfer lines and outer arc intersecting lines, the correction rod is of a cylindrical structure integrally, the chamfer lines and the outer arc intersecting lines are formed by each triangular chamfer and the correction rod, and included angles between the chamfer lines and the outer arc intersecting lines are inclined angles of inclined end teeth. By using the device and the method, the end teeth with high precision can be processed on a general machine tool.