A waterproof socket includes an inner core fixing base disposed between a retention frame and a socket base. Lower insertion holes are coaxial with an output terminal and are formed in the inner core fixing base. An accommodating groove is formed between two lower insertion holes. A waterproof inner core is disposed in the accommodating groove. The waterproof inner core includes a main body movably inserted in the accommodating groove. Two upper seal doors are sealed at upper insertion holes of the retention frame and are disposed on two upper sides of the main body, and two swing rods are symmetrically disposed below the upper seal doors. One end of each of the swing rod is hinged to the main body, and the other end of the swing rod is provided with a lower seal door for sealing the lower insertion holes of the inner core fixing base.