The task of electric power companies is to achieve their economic targets and social responsibilities. As one of the promising methods to make these targets come true, asset management are getting more and more attention, and the life cycle cost management (LLCM) is an effective tool of asset evaluation. To optimize the electrical equipment life cycle, and aiming at some problems in the current equipment maintenance research, which includes ignoring the influence of maintenance on equipment failure rate, ignoring the trend of continued deterioration during the operation of equipment and so on, this article introduces the deterioration theory in the field of mechanical engineering. This essence of this method can be regarding as searching the balance between the value of equipment themselves and the benefits the power systems brings, between LCCM and equipment maintenance, and finally, between technologies and management of power system. Based on this method, this article deduces the relationship of the reliability of equipment in each maintenance circle, and constructs the maintenance strategy optimization model of equipment based on risk combined with the definition of risk and service age reduction factor. In the end, this article employs the theory into a practical example and calculate the optimal maintenance interval, and finally compares it with traditional preventive maintenance.