The invention relates to the field of roasting furnace production running, in particular to a communication joint and a roasting furnace running method. The communication joint comprises a hollow body, the two ends of the hollow body are provided with connectors in the same direction, and outlets of the connectors are vertical to the hollow body; and the hollow body and the inner surfaces of the connectors are each provided with a flame retardant coating. The communication joint is designed according to the bridge joint requirement of a roasting furnace fire way, the connectors at the two ends are connected with a fire way hole, the hollow body and the inner surfaces of the connectors are each provided with the flame retardant coating, and therefore the high temperature resistance aim is achieved. When the roasting furnace fire way has abnormal blockage, the problem of blockage is solved through bridge joint of the communication joint, normal running of the related fire way on the fire way upstream is guaranteed, normal running of the related fire way on the fire way downstream is guaranteed, normal running during production is achieved, and bad effects caused by fire way blockage is effectively avoided.