The invention discloses a submarine pipeline terminal of an underwater isolation valve. The submarine pipeline terminal comprises an anti-sinking plate, a supporting structure installed on the anti-sinking plate, an underwater isolation valve, an execution mechanism of the underwater isolation valve, a process pipeline, an expansion bend connector and a valve protective structure. The supporting structure is arranged in the middle of the anti-sinking plate, the underwater isolation valve and the execution mechanism of the underwater isolation valve are arranged on the supporting structure, and the valve protective structure is a cover which covers the underwater isolation valve and the execution mechanism of the underwater isolation valve. According to the submarine pipeline terminal of the underwater isolation valve, necessary supporting and limiting can be provided for the underwater isolation valve to ensure that the underwater isolation valve will not vertically sink or horizontally move in the running process; in addition, the underwater isolation valve can be in smooth transition with a submarine pipeline expansion bend through the connector; meanwhile, the underwater isolation valve is protected, and it is ensured that the underwater isolation valve cannot be damaged by impact of fallen objects in water and an underwater robot and traction of a fishing net.