For the problem that the machining precision of film cooling hole of aero-engine turbine blade is low and the recast layer is difficult to be removed. A new film cooling hole process which is mainly based on the thought of using EDM to drill and using grinding to expand is proposed. Grinding experiment was carried out on the film cooling hole machined by EDM using the special fine CBN grinding wheel. The result shows that after the grinding process, the roundness of the film hole is reduced by 50.9%, the standard deviation of the hole size is reduced by 90.7%, the surface roughness is reduced by 65.9%, and the recast layer is completely removed, proving the feasibility of the grinding approach of film cooling hole of aero-engine turbine blade