Abstract: Instructor Operating Station（IOS） as the center of command and monitor is one of the most important components of commercial aircraft flight simulators.According to the application requirements of flight simulators，the advanced IOS system is designed and implemented.The overall structure，composition principles and network configuration are described.The function is decomposed using modular method and the four-classification function method is proposed.Using Object-Oriented technology，the architecture of software class libraries，communication frame and man-machine interactive interface of IOS system are designed.Application of the developed IOS shows that the IOS has complete function，abundant displayed information，friendly interface，steady running performance and easy operation.It also has a certain versatility and augmentability.