The invention provides a turning fixture for the inner hole and a plane of a spiral bevel gear, which can be connected to a lathe and perform turning for the inner hole and plane of the spiral bevel gear so as to improve the processing efficiency and ensure the processing quality. The turning fixture comprises a fixture seat connected with a spindle of the lathe; a fixture body is fixed on the fixture seat and provided with at least three positioning balls which are uniformly distributed in the circumferential direction of the spiral bevel gear; three pressure plates sleeved on three pull rods are used for tightly pressing the spiral bevel gear on the positioning balls; the lower end of the pull rod passes through the fixture body and is connected with a fork-shaped plate; the central part of the fork-shaped plate and a movable slider form a spherical pair; and the movable slider is provided with a central screw connected with a spindle oil cylinder of the lathe.