Abstract: In this paper, a Dynamic Layered-Graph(DLG) routing model based on Cognitive Radio(CR) mesh networks is proposed .The channel which Cognitive Radio node can sense is modeled by a two states discrete time Markov chain and a model depict Cognitive Radio networks topology and connectivity is built up. A cross-layer design dynamic interface assignment policy is also proposed based on the model. Simulation results show that as the aspect of the adaptability of the dynamic access spectrum and depicting the topology of Cognitive Radio Mesh networks, the performance of Dynamic Layered-Graph model outperforms the Static Layered-Graph(SLG) model.