Embodiments of the present disclosure belong to the field of valve sealing, and in particular, relate to a test device for simulating sealing performance of a one-way valve. A box is provided with a gas inlet pipe and a gas outlet pipe, the gas inlet pipe is communicated with a gas source, a detection device is communicated with the gas outlet pipe, the detection device is used to detect detection gas input into the box by the gas source, a sleeve is connected to the gas inlet pipe, one end of the sleeve is communicated with the gas source, the other end of the sleeve has a gas outlet, one end of a fitting piece is used to block the gas outlet, and the other end of the fitting piece is connected to a driving member, which is used to drive the fitting piece to move and rotate.