The paper introduces the communication system of vending machine based on Dex/Ucs and how to realize communication and data acquisition between terminal and vending machines on Platform Vb6 + Borland according to feature and communication theory of Dex. The core of the system is communication between terminal and vending machine which is realized via three-way handshake of Dex session layer. The format of data during transmitting is also based on Dex session layer Protocol. Implementation platform of the system is Vb6+C module which is a perfect combination of advantages of the two.