A positioning fixture for fixing an end face structure of an optical fiber splice closure, wherein the positioning fixture is used to limit a circumferential flange (D) of the end face structure of the optical fiber splice closure, and comprises a fixed clamp (1), wherein a movable clamp (3) is connected to the fixed clamp (1) by means of a first hinge shaft (2), a locking component is disposed between the fixed clamp (1) and the movable clamp (3) to implement a connection between the fixed clamp and the movable clamp, the fixed clamp (1) is provided with a first groove (4) distributed along a circumferential direction thereof, the movable clamp (3) is provided with a second groove (5) distributed along a circumferential direction thereof, and the first groove (4) and the second groove (5) cooperate to form a circular annular slot, wherein a slot width of the circular annular slot is greater than a thickness of the circumferential flange (D), the first groove (4) and the second groove (5) are both provided with feature lug bosses (6) that are distributed at intervals along their respective circumferential directions and used for clamping with the circumferential flange (D).