Mechanism and system for transmitting vehicle emergency message based on DSRC

The invention relates to a vehicle urgent information sending mechanism and a system based on a DSRC, when a vehicle encounters a unusual condition during driving, a urgent information is automatically produced, the urgent information is sent in preference to other information. Vehicles which receive the urgent information determine whether the urgent information is transmitted at once according to respective retransmission distance threshold. Corresponding retransmission distance thresholds are determined according to different existing environment, network spending is reduced, simultaneously, the urgent information is further guaranteed to be rapidly sent. The whole system of the invention substantially comprises a data vehicle position module, a data acquisition module, a memory, a processor and a data sending and receiving module.