Abstract: Dynamic spectrum access technology can ensure the rights of authorized users,while allowing cognitive users to temporarily borrow “idle”spectrum,which can effectively solve the scarcity of spectrum resources.For cognitive radio networks with only one channel but many data needs to be transmitted,a multipriority polling scheme based on loss mechanism is proposed.By applying the theory of Markov queuing theory,the average queue length and average queuing time of the system under equilibrium condition are obtained.Numerical analysis and simulation results show that the proposed mechanism can improve the queuing performance of cognitive radio networks and reduce the spectrum holes effectively.