AP-913 (Equipment Reliability Process Description) describes an equipment reliability process offered to assist member utilities to maintain high levels of safe and reliable plant operation in an efficient manner. This document based on AP-913 process document, this paper generally describes its determination by logic and analysis method. Combining with the types of failure and consequences in the actual problems, it created a more simplified maintenance strategy optimization mind maps (including the system stability, the design necessity, the economic efficiency, the equipment reliability four factors, refining the equipment and benefit related factors, its relationship and influence between the four are clarified), that can raise efficiency of maintenance and enhance the stability of the system. Through its application in the maintenance cases, it takes some cases for example: Increase the PM project of replacing the power board card of the transformer group, shorten the PM project cycle of the transformer group power transmitter, and change the control operation mode of the main transformer cooler;cancel the design of outdated manual working frequency excitation equipment and its PM items, cancellation of electric disk cabinet timer, etc. It is proved that the reliability of the equipment is improved after the implement of the maintenance strategy optimization. Time costs and labor costs are saved, and the cost of equipment procurement is decreased too. Responding to control the company’s cost positively, some ideas at the same time also can provide reference for other similar plant maintenance work.