In the realm of aerospace missions, there exists an urgent requirement for constructing a health status evaluation index system for spacecrafts. This paper undertakes a comprehensive analysis of the global development status of related technologies. It clarifies the principles for grading the health of spacecrafts, categorizing their health status into three distinct states: healthy, sub - healthy, and faulty. The faulty state is further subdivided into minor, emergency, and serious faults. Subsequently, the paper elaborates on the essential elements involved in constructing the health evaluation index system, which encompasses diverse information such as telemetry data. A hierarchical architecture is meticulously designed, consisting of a target layer, an element layer, and an index layer, and multiple evaluation indicators are proposed. Based on these, an evaluation system is put forward, constructed from two aspects: expert - knowledge - based subsystem assessment and intelligent analysis. Moreover, calculation methods for health scores at all levels are provided. Experimental evaluations of the health status of multiple spacecrafts are conducted. The results demonstrate that this method can effectively establish a health status evaluation system for spacecrafts, thereby assisting operators in accurately determining the health status of spacecrafts.