Aerospace environment has an important influence to modern weapon system performance. In order to generate accurate and standard synthetic environment data, building a synthetic environment data generation system is meaningful to simulation test. The system is based on international environment data standard Sedris and uses virtual test and distributed simulation technology. It implements atmospheric, infrared and electromagnetic environment data’s generation. According to different battlefield environment, using this system could complete synthetic environment’s modeling, specific computing, data transfer and visualization. The system improves test’s accuracy and validity. It also provides a data support for weapon system’s effective evaluation.