Abstract: The eight key parametersof fuzzy setsplastic hardening model were used for the sensitivity analysis, which was based on the orthogonal test method. By using of the test data in U.S.CASE test database, such as seidsand, the expectation and variance of the parameters can be obtained after a lot of calculation and the adopting of mathematical statistics correlation theory. Through comparison, the key parameters have been sorted by sensitivity. The result shows that themethod provides necessary reference forthe selection of parameters of fuzzy setsplastic hardening model. Meanwhile, the method can be applied to the secondary development of the model in order to reduce workload in the process of parameters back analysis and screening.