A multi-stage burglar-proof lock core comprises a lock head, a multi-stage lock core installed in the lock head, and a plurality of elastomers inserted into the multi-stage lock core. Two parallel inserting holes are radially formed in the lock head with an angle of 45 degrees to the slots in the lock core. The lock core is formed with at least two core units. Each core unit has a through hole along the axial center of the lock hole. Each core unit has a penetrating hole aligned to a respective slot. Each penetrating hole is communicable to the through hole. The lower pin can enter into the penetrating hole of the lock core; while the elastomers are embedded into the slots and the inserting holes. When rotating a selected one of the core units through 45 degrees, the t through hough holes of all core units are aligned to be as a continuous keyhole.