The invention relates to a determination method for an interference film hole machining angle, and belongs to the technical field of aero-engine turbine blade machining. The determination method comprises the following steps that, a machine tool coordinate system (x, y, z) is established according to a position axis of a machine tool, a horizontal rotation axis of the machine tool serves as a B axis, and a vertical rotation axis of the machine tool serves as a C axis; according to the machine tool coordinate system (x, y, z), an initial coordinate of the interference air film hole and an initial coordinate of a bending guider are determined; and according to the initial coordinate of the interference film hole and the initial coordinate of the bending guider, when the B axis and the C axis are rotated to drive the interference film hole to rotate towards the bending guider, the rotation angle of the B axis and the rotation angle of the C axis are the machining angle of the interference film hole. According to the determination method, on the premise that the design performance of a turbine blade air cooling system is not reduced, shielding of a blade structure is effectively avoided, electric spark machining of the interference film hole is achieved, and therefore the design performance of an advanced aero-engine is met.