The high-speed on-off valve driven by smart materials has better dynamic and static characteristics than the electromagnetic high-speed on-off valve. Aiming at the disadvantage of small output force of traditional cantilever structure piezoelectric bimorph, a pneumatic high-speed on-off valve based on piezoelectric bimorph is studied in this paper, and a simply supported beam structure fixing method is proposed. The fluid structure coupling of the piezoelectric elements is analyzed with the COMSOL. The key structural parameters of the valve are optimized, and the prototype is tested. The experimental result shows that the operating frequency bandwidth reaches 280 Hz, and the maximum flow is 30.7 L/min at the pressure differential of 0.3 MPa.