In order to describe the degradation process of key components more accurately, the influence of maintenance activities on the degradation rate and initial degradation of equipment performance was proposed when the Wiener degradation process is used to model equipment. Based on the established model, the probability distribution of the remaining useful life is obtained based on the concept of first arrival time. According to the predicted value of the remaining useful life, the aperiodic performance detection is carried out as the time interval, and the degradation value obtained is compared with the fault threshold and maintenance threshold, the corresponding maintenance activities are made. Then, taking maintenance threshold as variable, Monte Carlo cycle simulation method is used to select the optimal value to achieve the minimum cost-effectiveness ratio in the condition-based maintenance strategy of key components, so as to reduce the cost-effectiveness ratio during the use of equipment. Finally, the ship component gyroscope is taken as an example, the simulation results show that the relative error of the predicted the remaining useful life value is less than 0.3%. When the maintenance threshold is set as 8.02 degrees/day, the efficiency ratio reaches the lowest as 199.996 yuan/day. The simulation and comparison between periodic detection of condition-based maintenance strategy show that the proposed method can save the detection cost, cut down the number of the breakdown maintenance, decrease the maintenance cost, and effectively reduce the cost-effectiveness ratio.