In cognitive radio mesh networks, the unlicensed users are allowed to use spectrum opportunities under the restriction of protection of licensed users. The transmission operation of unlicensed users packets is typically done through multiple mesh routers. In the case of a large amount of packet retransmissions, the performance of the whole network system may degrade. To solve this problem, a queueing buffer based priority scheme for mesh routers is suggested. Based on this scheme, the uplink transmission performance of unlicensed users in cognitive radio mesh networks is studied under the condition of imperfect spectrum sensing. Numerical evaluation results show the feasibility and effectiveness of the suggested priority scheme.