Abstract: The present disclosure discloses an air valve for a tire bead seater solves a problem that an inner piston in the air valve is prone to be difficult in moving upwards or downwards due to a thermal expansion and contraction of the piston and has a poor sealing performance when using a tire bead seater, and it is difficult to replace a barrel of the air valve with barrels in other different shapes to satisfy different inflation requirements. The air valve of a tire bead seater includes an inflation cylinder, where a top end of the inflation cylinder is provided with a cylinder mouth. In the present disclosure, through a cooperation between an upper sealing ring and a lower sealing ring that are made from PEEK material, it has a good temperature adaptability and a small deformation.