The routing method for wireless transport service comprises a step of receiving a unicast frame from an associated client; determining whether a destination of the unicast frame is locally associated. A wireless node delivers the unicast frame to a final destination if positive, otherwise, determining whether an associated transport device of a destination can be determined. The WITnet header is added and the associated transport device of the destination is put in an auxiliary address field if positive, otherwise, the next step is performed to add the WITnet header and put an address of a default edge device in the auxiliary address field. The next step is setting a tunnel frame flag, and then delivering the unicast frame to a next-hop toward the auxiliary address.