In the past few decades, analytical models for maintenance optimization have been extensively investigated. As research continues, the cases considered during the mathematical modeling are much more practical, as well as complex, which brings many difficulties for solution. In this paper, we present an exact method for solving the selective maintenance model considering multiple maintenance actions. The solution procedure is discussed in detail. Moreover, an example is adopted to verify its efficiency. Compared with total enumeration method, the proposed method can significantly reduce the solution space (about 42.46%). What's more, unlike some intelligent algorithm, this method can always give out an optimal solution. Finally, the effects of available resources on solution space are discussed.