The invention provides an underwater power supply connector which comprises a son connection assembly and the mother connection assembly. The son connection assembly comprises connection copper pieces, a son sealing cladding, a rotation head and son conductive wires. The connection copper wires are connected to the son conductive wires. The son sealing cladding and the rotation head coat the connection copper pieces and the son conductive wires. The underwater power supply socket has the advantages that multiple sections of power supply lines are connected to use, the long distance underwater arrangement of a power supply line is realized, the underwater power supply connector is adapted to requirements of fishing grounds, and a technical problem of the fishing grounds due to insufficient wiring space is solved.