The occurrence of fault would greatly afect the remaining life of ofshore wind power transformer. In this paper, the fault events during the operation of the ofshore power transformer were analyzed based on the fault tree theory and the structure function of the transformer fault event was established with considering the operation environment to propose the risk model of transformer fault events. The Monte Carlo method was used to sample the risk model, and the fault risk coefcient of the operation for the ofshore transformer was obtained. Taking the infuence of fault events into the remaining life of the transformer, a Life estimation correction model for ofshore wind power transformer was established, which provides guidance for the optimal design and early fault warning of ofshore transformers.