The invention relates to a wireless tire pressure monitoring system provided on a tire or a rim of a vehicle. The system includes: a magnetometer for measuring a magnetic flux value; a pressure sensor for measuring a pressure value within the tire; a controller for receiving the magnetic flux value measured by the magnetometer and the pressure value measured by the pressure sensor, and determining whether the magnetic flux value fluctuates; and a wireless signal transmitter in signal communication with the controller, and controlled by the controller, wherein when the controller determines that the magnetic flux value fluctuates, the controller activates the wireless signal transmitter or raises the transmitting times per minute of the wireless signal transmitter and the wireless signal transmitter transmits a signal which represents the pressure value. The invention also relates to a method for operating a wireless tire pressure monitoring system.