The invention discloses a road monitoring system for a multivehicle complex road segment, and the system is characterized in that the system comprises a radio frequency identification tag disposed on a vehicle, and a plurality of radio frequency identification readers disposed on a road surface; the radio frequency identification tag has a function of signal transmission, and a transmitted signal comprises the information of a vehicle body and the state information of the vehicle; the radio frequency identification readers are arranged on the road surface in an ordered manner, and are used for reading the signals transmitted by the radio frequency identification tag of the vehicle in real time. The system is achieved based on the radio frequency recognition technology, is high in precision, is simple in structure, and is low in cost.