In order to combine the theory study and material object research together properly, this paper designs and implements a NC-OFDM system of CR based on USRP2, and presents the flow path of both software and hardware in detail, meanwhile, it also presents the solution to the key problems. The paper introduces a fast and effective self-adaption algorithm based on traditional algorithm and Pruning algorithm. The software and hardware simulation results show that this system is available to implement the wireless communication based on the USRP2. And the proposed algorithm not only can reduce the time of dealing with data effectively, but also can improve the robust of data transmitting and enhance the performance of the whole system.