The invention discloses a conversion interface used for electric power protection. The conversion interface comprises a plug and a socket; the plug and the socket are matched in an inserting manner; the plug comprises an upper shell, a contact pin and an upper locking mechanism; a first groove and a third groove are formed in the end plane of the upper shell; the contact pin is fixedly connected in the first groove; a second groove connected with the third groove is formed in the side surface of the upper shell; an elastic section of the upper locking mechanism is fixedly connected with the bottom surface of the second groove; a locking section of the upper locking mechanism is glidingly matched with the second groove; the socket comprises a lower shell, an inserting sleeve and a fixed column; the fixed column is fixedly connected with a base shell, and glidingly matched with the third groove; the fixed column is tightly clamped and matched with the locking section of the upper lockingmechanism; a fourth groove corresponding to the contact pin is formed in the lower shell; and the inserting sleeve is fixedly connected in the fourth groove and glidingly tightened and matched with the contact pin. In all, the conversion interface is convenient to mount and detach, high in stability, and capable of unifying switch cabinet relay protection apparatuses of different wiring modes, thereby achieving a time-saving, labor-saving, convenient and efficient effect.