Abstract: To improve the throughout of the networks and develop the integrated services LAN, a new medium access mode of LANdouble token and double loop protocol is put forward firstly, and then the mathematical modeling research on it is carried through. After the service time being assumed short and the virtual waiter being put forward, the system of double token and double loop LAN which has two physical waiter is equivalent to the followed queue model of the interim service with one virtual waiter. The simulation experiment shows that this double loop LAN can not only improve the dependability of the loop LAN, but also enhance the throughput of the networks in a large range, so the academic foundation for the application of this double loop LAN is provided under the condition of the integrated services.