The utility model relates to a flexible pipeline under pressure leaking stoppage connecting device, including the connecting device body, the connecting device body is provided with the leaking stoppage seat, the fixed lug that is provided with in leaking stoppage seat one side, the cylinder form is set to the lug, leaking stoppage seat and lug all are provided with the through -hole, through -hole upper end inboard is provided with the internal thread, the connecting device body still is provided with the screw, screw and internal thread phase -match, leaking stoppage seat lower surface is provided with the gasket, be provided with the drainage tube in the through -hole, drainage tube one end is provided with the pointed end, the drainage tube is provided with the different body of a plurality of diameters. The utility model relates to a flexible pipeline under pressure leaking stoppage connecting device need not weld the effect that just can reach the pipeline under pressure leaking stoppage, can not influence the production operation simultaneously, can guarantee continuously going on of production, saves cost of maintenance, guarantees the productivity effect, is suitable for the leaking stoppage of various pipe diameters moreover.