Abstract: In the vibration test of spacecraft, some of its components will undergo the processes of aging, even failure because of long time use. For a qualitative analysis, the FMEA method is used to analyze the overall test bench, and the weakest link for the test bench is identified. For a horizontal sliding table's reliability series model in the subsystem, it is shown that it complies with the weak correlation theory. Then, the traditional reliability formula and the weak correlation are used, respectively, to predict the reliability of the model. A comparison shows that the weak correlation is better than the traditional reliability formula under the condition that all parts are not completely independent according to the actual situation. That is to say it is more effective for the reliability assessment of the horizontal sliding bench. The method is of theoretical and practical significance for mechanical system reliability calculations.