The invention discloses an underwater short circuit prevention separating electric connector capable of synchronous unlocking. The underwater short circuit prevention separating electric connector comprises two same monomer electric connectors, a connecting mechanism (108), a lock sleeve (106), a socket flange (18) and a plug flange (22). Each monomer electric connector further comprises a split plug (107) and a split socket (105), each split plug (107) is internally provided with a center pillar (12), each split socket (105) is internally provided with a middle pillar (2) and a reset spring (10), the middle pillars (2) limit the reset springs (10) inside the split sockets (105), and the connecting mechanism (108) also comprises a pull bar (23), steel balls (24) and an unlocking spring (25). According to the invention, the two monomer electric connectors and the connecting mechanism (108) form an integral electric connector through switching of a switching flange, and through controlling the connecting mechanism (108), synchronous locking and synchronous unlocking separation of the two monomer electric connectors are realized. At the same time, the monomer electric connectors employ three-layer structures so that a shor circuit can be effectively prevented.