The invention belongs to combination of a machining technology and a surface treatment technology of parts, and particularly relates to a chromium leakage prevention machining method for aerial rotary parts such as a helicopter undercarriage part. Currently, since deformation control is difficult and the deformation direction and size are both unpredictable, the chromium leakage situation of the large helicopter undercarriage rotary part is common, and the percent of pass of the large helicopter undercarriage rotary part is small; and meanwhile, the repair period of the chromium-leakage part is long, meanwhile, repeated chromium leakage can cause part scrapping, and large economic loss is caused. According to the chromium leakage prevention machining method, before and after chromium plating of the aerial rotary parts, the lathe worker operation specification, the grinder operation specification, a uniform datum alignment method, a chromium plating uniform control method, the surface cleaning requirement, the treatment requirement of a piece returned for repair after chromium stripping and a grinding burn control method are formulated to form the chromium leakage prevention machining method for the aerial rotary parts.