The paper discussed the credibility evaluation of the momentum wheel bearing subassembly in a satellite.The simulation credibility evaluation was conducted by calculating the similarity between the simulation output and physical experimental output

which was based on the relationship between the credibility and the similarity.Similarity elements between simulation output and physical experimental output were determined

and a quantitative function was constructed.Then

the paper improved the computational methods of analytic hierarchy process(AHP) that was used to determine the weight of elements.Consequently

the simulation credibility of a momentum wheel bearing subassembly was evaluated through the method.