A traffic flow dynamic guiding method based on a region block includes: building communication connection with a cloud server by a vehicle-mounted terminal; performing data acquisition by the vehicle-mounted terminal, and uploading acquired data to the cloud server; receiving feedback of the cloud server by the vehicle-mounted terminal which is including an accident occurring probability of a current automobile in a set range of a current road section; sending the probability to a driver in a human-computer interaction mode; receiving communication addresses, sent by the cloud server, of the surrounding vehicle-mounted terminals in the set range by the current vehicle-mounted terminal in order to build a connection relationship with the surrounding vehicle-mounted terminals; performing running and updating after the region block relationship is built; performing traffic flow guiding on traffic accident information and performing traffic flow guiding on official vehicles by using the region block relationship.