The invention discloses a pipeline port stopper, which comprises a transmission lead screw, a bearing head, an actuator plate, an extruding bowl, at least two locking sliders and a packer ring, wherein the transmission lead screw is provided with a pin joint end, a threaded section and an operating end; the bearing head is pivoted with the pin joint end of the transmission lead screw; the actuator plate has a threaded hole which is matched with the threaded section of the transmission lead screw; the extruding bowl is arranged slidably between the bearing head and the actuator plate, and has an inclined sliding conical surface and an extruding end face; the locking sliders are linked the actuator plate, the lower surfaces of the locking sliders are axially and slidably matched with the sliding conical surface of the extruding bowl, and the locking sliders are driven by the actuator plate to ascend along the sliding conical surface and are locked in a radial expanding state; and the packer ring is arranged between the bearing head and the actuator plate, and is extruded by the extruding end face of the extruding bowl to be in the radial expanding state so as to realize plugging.