The utility model relates to a thread-sucking port-jacking device, wherein a negative-pressure switch is arranged on a thread-sucking assembly, the outer side of the thread-sucking assembly is vertically provided with a cylinder, a piston rod of the cylinder is in driving connection with the upper end of the floating part of the thread-sucking assembly, and the negative-pressure switch and a control valve of the cylinder are respectively and electrically connected with a controller through leads; the control valve is a valve terminal; the controller is a programmable controller; and the lower end of the piston rod of the cylinder is provided with a counter weight. Through the thread-sucking port-jacking device, not only can the purpose of normally conveying tobacco threads be ensured, but also the effects of reducing the breakage of the tobacco threads, increasing the filing value and reducing the consumption can be achieved. Meanwhile, the damage to the movable joint of a thread-sucking port is reduced, and the service life of the thread-sucking port is prolonged.