The invention discloses a vehicle-mounted traffic light anti-blocking prompt method. A wireless signal transmitting device arranged on an opposite traffic light and a vehicle-mounted signal receivingand displaying device arranged in a vehicle are comprised. The wireless signal transmitting device is electrically connected with the traffic light, and comprises a processor and a wireless transmitter. The vehicle-mounted signal receiving and displaying device comprises a base and an LED display arranged on the base. An indicating arrow and an indicating lamp are arranged on the LED display. A solar panel is arranged on the back of the LED display. The vehicle-mounted signal receiving and displaying device further comprises a processor and a wireless receiver. According to the invention, thestructure design is reasonable; through synchronous wireless connection with the traffic light of an opposite lane, the problems that the sight is blocked by a front large-scale vehicle and the user cannot see the traffic light in the prior art are solved; the driving safety is improved; and the traffic safety of a road is ensured.