Chain type under-pressure leaking stoppage device

The utility model relates to the technical field of pipeline leaking stoppage, and aims to provide a chain type pressure leaking stoppage device to solve the technical problem that a leaking stoppage plate is easy to twist or an operating handle is easy to tip over in the using process of a leaking stoppage device in the prior art. The chain type under-pressure leaking stoppage device comprises a leaking stoppage plate, a flexible fixing structure and an operation handle rotating around the central axis, the operation handle is used for applying downward acting force to the leaking stoppage plate, a balance weight pressing block is rotationally assembled at the lower end of the operation handle, a mounting hole is formed in the upper end of the balance weight pressing block, and a balance bearing fixed to the operation handle is arranged in the mounting hole. The leakage stopping plate is prevented from being twisted and deviated by the operation handle; a mounting structure for detachably assembling the leak