Abstract: A TPMS transmitter (100) fixing structure, comprising a valve stem and a core rod (200) in the middle of the valve stem, the core rod (200) having a connector suitable for connecting to the TPMS transmitter (100), and also comprising a protruding part protruding outward along the radial direction of the valve stem, such that, when the valve stem is mounted on a wheel rim (300) of an automobile, the protruding part is in contact with the wheel rim (300); adding a protruding part to the valve stem can counteract the rotational torque produced by the eccentricity and centrifugal force of the transmitter to forcefully prevent rotation of the transmitter during operation, and limits the mounting direction of the TPMS transmitter, ensuring that the TPMS transmitter is not biased when mounted on the wheel rim, and effectively reducing the risk of the loss of function or reduction in performance of the TPMS transmitter due to biased or backward mounting of the TPMS transmitter.