The utility model relates to a steel factory converter high temperature flue gas field of handling, the venturi tube closed loop electro -hydraulic control system that adjusts is carried out in heavy top operation to adjustable larynx circumferential weld venturi tube promptly. It includes device subtotal control section. Device part including a sealed box, the seal box is internal to have pneumatic cylinder, hydraulic stem, there is the tray arm hydraulic stem upper end, tray arm both ends are connected with venturi tube weight lifter respectively, the sensor lifter is also connected to the connecting rod of connecting on the hydraulic stem simultaneously, the pneumatic cylinder is connected with servovalve, electric node manometer, hydraulic fluid tank, control motor. Control section include acquisition unit, management module, executable module. Simplified overall structure, equipment is small, reduction equipment investment cost 8-10 times, and the installation maintenance of being convenient for, convenient operation, it is convenient to regulate and control, the dependable performance.