The basic principles and common methods of enhancing the microcomputer protection's reliability by using Fault-tolerant Control have been proposed,based on the analysis of the theory of Fault-tolerant Control.The sensor's Faulttolerant Control of microcomputer protection system has been discussed intensively,and the working principle of its fault detection and fault tolerance is analyzed.For example,the feeder protection combined with Fault-tolerant Control of traction substation has been proposed.Fault-tolerant Control brings a new way for microcomputer protection to enhance its reliability.