Traditional modal test of spacecraft is usually used to examine its finite element model, but the parameters of the finite element model are always modified through artificial adjustment, which isolates modal analysis from modal test, and influences the precision of subsequent analysis, research period and funds etc. In order to change the present situation of modal analysis and test of spacecraft, this paper introduces the feasibility of modal analysis-test system in theory, and based on the Virtualab-Nastran software platform, gives an example of a scaling cabin, implements the complete procedures of modal analysis-test system, including pretest analysis, modal test, model updating etc, which closely relates modal analysis to test, corrects the finite element model rapidly according to the test results, makes the analysis results close to test results, and achieves precise modeling.