As a new networking topology, Wireless Mesh Networks (WMNs) have advantageous properties in terms of robustness, range extension and density, but also have significant potential disadvantages, which determines some classical load-balancing algorithms are not very suitable for WMNs. In this paper, we propose a novel load-balancing algorithm to improve the networks performance. The new scheme, which is called CHLB, guarantees the QoS for different data streams through cross-layer design to accomplish the load balance without bringing heavy extra-load. Simulation results show that the proposed algorithm can give the effective load-balancing results and remarkably improves the WMNs performance.