A tire pressure monitoring system (1) includes a plurality of tire pressure sensing modules (2) and an information display module (3) in information connection with the tire pressure sensing modules (2). The tire pressure sensing modules (2) are installed at respective tires of a vehicle to transmit tire condition information (D2) of the respective tires and device identification codes (D1) to the information display module (3). The information display module (3) includes a data processing unit (32) associating each of the device identification codes (D1) with a device selection code and a stepless knob (34) controlled to output at least one selection signal to the data processing unit (32). Upon receiving the selection signal, the data processing unit (32) determines the corresponding device selection code according to the selection signal to read the corresponding tire condition information (D2), thereby allowing a user to quickly learn the tire condition of any tire of the vehicle.