A tire pressure sensor including a body, a sealing member and a circuit and signal transmission apparatus is provided. The body includes a first casing, a first hole, a receiving portion and a second casing. The receiving portion connects with the first hole passing through the first casing. The sealing member includes a second hole that is set through the rubber component of and communicates with the first hole. The sealing member is located in the receiving portion. The circuit and signal transmission apparatus includes a circuit apparatus and a hole. The hole positioned on the surface of the circuit apparatus communicates with the first hole and second hole to form an air seal channel. The air pressure of the tire is injected through the air seal channel into the hole, and the tire pressure sensor can detect the pressure and temperature of the air of the tire.