The invention relates to a road accident prompting method based on vehicle-road collaboration. The road accident prompting method based on vehicle-road collaboration comprises the following steps that S1, vehicles upload vehicle information to a roadside unit system periodically, the roadside unit system processes the vehicle information, and if an accident occurs, a broadcasting message of a fixed format is generated, and the message is broadcasted to travelling vehicles close to the area of the accident; S2, drivers of the travelling vehicles receiving the broadcasting message check the broadcast message list of the vehicles, and if the broadcasting message does not exist, the drivers judge the movement directions, the position relationship and the distance information of the vehicles and the vehicles in the area of the accident according to the broadcasting message, and then the drivers decide to selectively forward the message or abandon the message. Compared with the prior art, prompts can be effectively provided for following vehicles in real time by the adoption of the road accident prompting method based on vehicle-road collaboration, the spreading range is wide, the efficiency is high, the practicability is good, and popularization is easy.