Abstract: Co-channel interference is serious when multiple Bluetooth piconets coexist in a limited area. Therefore, a co-channel interference suppression method based on the channels switching is proposed. With the method, channels may switch from one to another when a piconet carries out retransfer packets. In order to approach practical scenarios and considering that identical frequency channel in different piconets may not lead to co-channel interference, some issues are taken into account in the analysis process, such as the return packets, the frequency hopping guard time, and the coexistence of three packet sizes. Simulations are carried out on the network performance of piconets. The simulation consequence indicates that the methodology can reduce the PER, and the throughput of piconet is improved effectively. And particularly, when the range of piconet number is set from 14 to 57, the throughput can go up 260 kbps.