Abstract: The DC/DC converter parallel system offers advantages in power expansion and redundancy, making it widely applicable in power supply and distribution systems. With the increasing emphasis on energy conservation and environmental protection, electronic equipment often operates under light load conditions for extended periods; thus, enhancing light-load efficiency through a DC/DC converter parallel system becomes essential. The on-off control method can improve the efficiency of the parallel system, but it cannot achieve the redundancy of the parallel system. A new redundancy control method is proposed based on the on-off control method, which simultaneously achieves high light-load efficiency and n+1 redundancy of the parallel system. The principle and existing problems of the on-off control method are introduced first, and then the circuit and working principle of the new redundant control method are demonstrated. The circuit parameters of the three-converter parallel system and their transient overshoot voltage are calculated. Finally, the simulation results show that the parallel system can achieve n+1 redundancy. The simulation waveforms show that the 20% load efficiency of the parallel system reaches 89%, which is 5% to 10% higher than other similar products; the current-sharing accuracy is 4%, and the load-transient overshoot voltage is 6%.