Abstract: Aiming at the difficulties of "human-in-the-loop" synthetic training simulation such as large scale, many entities, decentralized deployment and many heterogeneous systems. After study the construction of US Army synthetic training environment, a sustainable evolution cloud service architecture of distributed synthetic training simulation based on TISA middleware is designed, and a composable multi-level synthetic training simulation application model is put forward. It solves the technical problems of distributed training simulation, which are real-time interconnection and interoperability, consistency of battlefield environment, model composition and reuse, simulation as a service, etc. It provides technical supports for large-scale "human-in-the-loop" tactical confrontation exercises and research exercises, which helps to improve combat effectiveness.

Key words: training simulation, human in the loop, simulation architecture, simulation as a service