Vehicle-mounted WTB message recorder

The invention provides a vehicle-mounted WTB message recorder. The vehicle-mounted WTB message recorder comprises a WTB interface, a WTB decoder, a first processor, a high speed RAM, a voltage measuring circuit, a capacitor circuit, and a power supply circuit; the WTB interface, the WTB decoder, and the first processor are connected successively; the first processor is connected with the high speed RAM; the voltage measuring circuit is connected with the power supply circuit, the first processor, and the capacitor circuit respectively; and the capacitor circuit is connected with the high speed RAM. According to the vehicle-mounted WTB message recorder, when it is detected by the voltage measuring circuit that the voltage of the power supply circuit is lower than a threshold value, read-write message recording is stopped, and the RAM is supplied with electricity so as to avoid message record loss caused by sudden power failure or low voltage, and incomplete message recording caused by message record loss; and in addition, the writing speed of the high speed RAM is high, so that timeliness of write operation of message recording is improved, message recording loss caused by non-timely processing is avoided, and incomplete message recording caused by message recording loss is avoided.