The utility model relates to a novel valve of pulmonary trunk membrane open shaper, the valve open the shaper and be equipped with metal guiding sleeve pipe, valvotomy knife, metal guiding sleeve pipe and valvotomy knife link together, the valvotomy knife be equipped with inner core, tip, tip dew in metal guiding sleeve pipe outside, the valvotomy knife head be equipped with the sword groove, the sword groove has at least threely, the sword inslot is equipped with the knife, the knife between the circle diameter that encloses should be less than the diameter of the lamella of pulmonary artery ring own, there is the fixed point at the knife top, the inside fulcrum that is equipped with of fixed point. Its advantage shows: clinical use is convenient, and safe and reliable once takes shape, shortens operation time, reduces postoperative intervention rate again, according to infant lamella ring diameter size, there are different models available, simple structure is suitable for batch production, and application scope is wide.