Abstract: The extensive application of modern machinery has put forward higher requirements for the safety and reliability of the power system of drilling rigs. In order to ensure the smooth application of electronic equipment on the complex and severe environment of drilling rigs, besides improving the reliability and electromagnetic compatibility of the equipment itself, it is necessary to increase the redundancy and improve the quality of power supply. This paper mainly analyzes the power supply redundancy and UPS power supply. Combined with the actual application of offshore drilling rigs, a feasible scheme has been put forward and has been applied. The application has achieved good practical results in practice, which provides a useful reference for the design and optimization of the power supply reliability of drilling rig power systems.