The traditional serial RapidIO2.1 supports 3 lane modes (1×, 2×, and 4×). In 1× or 2× modes,  only 1 or 2 lanes out of 4 work for data-transmission while the others are in idle, which brings a result of bandwidth waste. In addition, one RapidIO interface can merely be connected with one destination. We design a dualchannel serial RapidIO interface based on traditional serial RapidIO interface protocol, which supports 14 transmission modes by a configurable crossbar switch on the PCS layer. It can connect 2 serial RapidIO interfaces simultaneously when it works in the dual-channel mode. This design improves the interconnected flexibility and transmission bandwidth of the RapidIO system. Simulation tests prove that the transmission bandwidth of the dualchannel RapidIO is approximately two times of that of the single channel RapidIO under 1× or 2× modes, and approximately equal to that of the single channel serial RapidIO interface under 4× mode.