A wireless field strength detection method and system achieve omni-directional signal detection of the field strength coverage of a ground radio station under a train dynamic condition and carries outstatistical analysis and grade evaluation on the field strength coverage quality of the radio station through comprehensive analysis. The system comprises an onboard speed sensor, a GPS antenna, a control radio station antenna, a radio station test unit, a field strength measuring receiver, a field strength measuring receiver antenna, a network switch, a test host, a display unit and a printer, and uses modern computer technology, sensing technology, a radio station control transmission technology, and wireless transmission technology to achieve high-speed acquisition in train operation and to complete the real-time detection of the signal strength field coverage area signal quality of the ground radio station; achieves synchronous parallel display of information, such as the field strength coverage area signal of the ground radio station, the train speed, a line state and the like, by a screen dynamic movement way by using a multitask multithread processing method, and achieve full automatic train positioning by using GPS.