Abstract: The degradation trend prediction results are important references for nuclear equipments in-service inspection and maintenance plan. But it is difficult to predict the nuclear equipments degradation trend accurately by the traditional statistical probability due to the small samples, lack of degradation data and the wavy degradation locus. Therefore, a method of equipment degradation trend prediction based on GM(1, 1)-Markov chain was proposed in this paper. The method which makes use of the advantages of both GM(1, 1) method and Markov chain could improve the prediction precision of nuclear equipments degradation trend. The paper collected degradation data as samples and accurately predicted the degradation trend of canned motor pump. Compared with the prediction results by GM(1, 1) method, the prediction precision by GM(1, 1)-Markov chain is more accurate.