The invention discloses an urban rail transit visibility monitoring system and method, and relates to rail transit technology. The urban rail transit visibility monitoring system comprises a visibility meter, a motoring unit, a monitoring center and a train-mounted terminal, wherein the monitoring unit is connected with the visibility meter, the monitoring center is in communication connection with the monitoring unit, and the train-mounted terminal is provided with a communication interface device and used for communicating with the monitoring center. The visibility of a specific position on a line or the whole line can be monitored in real time, an alarm is given for a driver to remind the driver of timely taking countermeasures such as speed reduction, and reliable guarantee is provided for driving safety.