with the development of finite element technology, finite element model is becoming to the main analysis tool. However, because some theoretic assumptions, unsuitable constraint and uncertain material property are applied, the simulation result of finite element model isn’t different from the testing data. In order to improve the design quality and safety of spacecraft, this paper deduced the formula of spacecraft finite element updating, developed the spacecraft finite element model updating system, the software mainly of five parts: the frequency response function calculation, the loading inverse solution, the finite element model updating, the data display, virtual experimentation. Software can complete exciting force inverse, parameter sensitivity analysis, parameters screening and finite element model updating. The calculation result of updated finite element model is in accordance with testing curve shape on the main vibration direction, first-order frequency error is ±5%, response error is ±10%. Software meet the need of finite element model updating, it provide a software base for spacecraft design.