In multi-channel wireless ad-hoc network, several nodes can transmit data simultaneously in different channels. Thus the overall network performance can be improved significantly compared to single channel network. Various multi-channel MAC protocols have been proposed to coordinate the usage of multiple channels between wireless nodes. However, multi-channel MAC protocols based on dynamic channel selection cause multi-channel hidden node problem in multi-hop wireless network. We evaluated the bad influence of multi-channel hidden node problem on the performance of multi-hop wireless network and showed that the problem decreases the performance of network as much as the use of multiple channels is not effective. This paper proposes a new approach of channel selection based on snooping. Nodes snoop data channels during idle times and then select an idle data channel within the carrier sensing range using both the snooping results and the channel usage information. We analyzed the throughput of DCSS in single-hop and multi-hop topologies. We also implemented multi-channel MAC simulator and performed simulation study with various scenarios. Our simulation results verify that the proposed channel selection approach can effectively avoid the multi-channel hidden node problem and improve the networkwide performance.