The utility model relates to the technical field of iron core calibration, concretely is a kind of iron core calibration jig, the utility model includes base, base upper end surface fixed mounting has main body, main body outer wall slidingly connected has support plate, main body outer wall is passed through and is set up vertical groove, vertical groove inside slidingly connected has slide, and the fixed connection of slide one end and support plate, movable plate is movably installed in the main body, main body outer wall is provided with adjusting mechanism, adjusting mechanism includes screw rod and connecting rod, screw rod is rotatably connected in main body outer side wall position, support plate is inserted in main body outer side wall position, and the main body inside and located movable plate below position is provided with inclined block, and the fixed connection of connecting rod one end and inclined block, movable plate bottom surface fixedly connected has connecting plate, the utility model is adjusted mechanism is set up, the height of support plate is accurately and stably fine-tuned, can satisfy the calibration demand of high-precision and multi-specification iron core, effectively improve applicability.