Abstract: According to the requirements of the manned spacecraft flight mission simulation, we propose a solution of the flight mission simulation platform for the manned spacecraft based on the characteristics of the manned spacecraft and the principles of the High Level Architecture(HLA), and realize the functions including the simulation management, the flight commands, the data recording, the data visualization, and implement the simulation platform which consists of those items for orbit, attitude, power, dynamics, etc. A typical application case is given, together with some key technologies including the platform development process, the three-dimensional visualization of the flight scene, and the software interface of the simulation model. Compared with the single flight mission simulation software, this platform covers more aspects of related fields and verification contents, and is more extendable for future updating. With the increasing complexity of the manned spacecraft flight mission, the simulation platform can meet new mission verification requirements by extending and reusing the current components. The simulation platform can be used for the verification of complex manned spacecraft flight mission designs, and it is also useful for the future simulation platform design and the development of other HLA-based spacecraft simulation systems.