The multichannel generator is a kind of special generator, which is developed to enhance power reliability in safety critical applications. This paper compares the dynamic performance computation for a 12/8 dual-channel switched reluctance generator (DCSRG) under single- and dual-channel operation modes. First, the static phase self- and mutual inductances are numerically calculated through finite element analysis (FEA). Based on the magnetic characteristics, the mathematical and simulation models of DCSRG under different operation modes are presented. In the dual-channel model, the effect of mutual coupling between phases of each channel in the DCSRG is considered. By using these proposed dynamic models, the different performances for the DCSRG under single- and dual-channel operation modes, such as generating process under closed-loop control, steady-state performance at different conditions, sudden change in load operation, and the operating status when changing from motoring to generating, are predicted and compared. Finally, a 12/8 DCSRG system is built for experimentation. The simulation and experimental results are also compared in the DCSRG system under different operation modes to verify the proposed modeling and analysis.