The invention relates to a rotary device lubricating oil substitution method including the following steps of S1 gathering a list of rotary devices to be lubricated, and identifying and classifying the devices using the same lubricating oil; S2 establishing a rotary device lubricating oil basic information base; S3 selecting lubricating oil, which is difficult in market purchasing and is not commonly used, to be oil to be substituted, and selecting the substitute oil from the information base based on the characteristic information of the oil to be substituted; and S4 carrying out the mixing experiment and compatibility experiment of the substitute oil and the oil to be substituted to determine whether the substitution is feasible. The method has the characteristics of scientification, process organization, and intelligentization, improves the work efficiency in the substitution of lubricating oil of rotary devices in industrial enterprises, and simplifies the types and number of the lubricating oil of the rotary devices; and moreover, the method is suitable for lubricating oil substitution of rotary devices in industrial enterprises, and particularly, for nuclear power stations having strict experimental data requirement on device lubricating oil.