The invention provides an automobile overload non-stop detection system and detection method based on RFID. The system includes a piezoelectric cable sensor, two groups of infrared grating instruments, an RFID reader, an RFID label, a computer, a DSP processor, a signal amplification circuit, a timer, and an LED display screen. A weigh-in-motion system is composed of the piezoelectric cable sensor, the signal amplification circuit, and the DSP processor, the dynamic weighing system is connected with the computer, the timer is connected with the infrared grating instruments, the infrared grating instruments are connected with the piezoelectric sensor, the RFID reader is connected with the computer, the RFID label is arranged on an automobile, and the computer is connected with the LED display screen. The weigh-in-motion system measures the weight signal during the automobile driving process and performs data processing; the timer records the automobile driving time; and the infrared grating instruments eliminate vehicle following phenomenon and are taken as the switch of the weigh-in-motion system. The system has the characteristics of high measurement precision, less damage to the pavement, and high adaptability.