The invention relates to a photoelectric underwater plugging connector. A plug is composed of an outer shell, a plug housing, a plug core, a first lip-shaped sealing element, an electrical contact pin A, a fiber plugging core B, a first adapter base and a first tail connecting element. A socket consists of a second tail connecting element, a second adapter base, a socket housing, a socket core, a socket sliding block, a second lip-shaped sealing element, an electrical contact pin C and a fiber plugging core D. When extending out of the inner cavity of the plug housing slightly, the left end of the first lip-shaped sealing element is closed and sealed; when retracting into the inner cavity of the plug housing, the left end of the first lip-shaped sealing element opens; when extending into the inner cavity of the socket sliding block, the right end of the second lip-shaped sealing element is closed and sealed; and when the socket sliding block separates from the right end of the second lip-shaped sealing element, the right end of the second lip-shaped sealing element opens and the outer shell and the socket housing are buckled and connected. Therefore, the operation is simple; underwater plugging is realized; the workload is reduced substantially; and underwater equipment can be repaired or replaced conveniently.