To improve the utilization of wireless spectrum resource, the dynamic spectrum access is used in the cognitive radio network. However, the advantages and disadvantages of Node target channel selection directly determine the spectrum access performance. Firstly, by comprehensively considering the two factors of the channel gain and spare time, this paper designs a channel selection mechanism so as to realize the goal of maximizing the system throughput. Then this paper introduces the concept of channel heat and puts forward a channel selection mechanism based on multiple attribute decision. The simulation results indicate that channel selection mechanism based on multiple attribute decision apparently improves the system throughput and spectrum utilization performance.