The invention discloses an auxiliary calibration mechanism for special-shaped steel processing, including a support mechanism, a lifting mechanism, a propulsion mechanism, a fine-tuning assembly, a vertical restraint mechanism, and a special-shaped steel calibration mechanism. The support mechanism includes a working table for providing a stable work flow, The lifting mechanism is installed on the bottom of the worktable, the propulsion mechanism includes a balance part and a driving part, and the balance part includes steel slats, inner pads installed at intervals outside the steel slats and welded on the inner pads Central screw. By setting the worktable, the groove and chute on the top of the worktable are used to fit and install the passive calibration combination. When the mold needs to be replaced, the operator only needs to rotate the deflection chainring counterclockwise, so that the pull rod on the deflection chainring comes The driving screw rotates, and at this time, the screw drives the screw sleeve, thereby prompting the steel slats to drive multiple sets of inner frames to shrink inward, which greatly facilitates the rapid replacement of the mold by the operator.