This paper introduces the IPS-200 computer interlocking processing system in detail.First,we review the basic concepts of interlocking handling systems and their importance in railway transport systems.We then give an overview of the design,functionality,benefits,and limitations of the IPS-200 system.Then,the hardware composition and software architecture of the system are discussed in detail,including security platform,communication function,man-machine interface and so on.In addition,we also in-depth analysis of the operating mechanism and performance of the system.Finally,the maintainability and reliability of IPS-200 system are described.