Abstract: Fan-coil unit(FCU)air-conditioning system is a typical form of air-conditioning system in buildings, but due to the complexity of the system, the hidden nature of the problem, the traditional practical teaching is confined to visit the cognition, students are difficult to deeply understand the operation and control methods and improve the awareness of energy saving. In order to solve the above problems, the paper uses virtual simulation technology to develop a virtual simulation experiment for operation and control of FCU air-conditioning. For three-speed and DC brushless two typical FCU, based on Dymola dynamic simulation software to establish FCU air-conditioning system simulation model, simulating the real system operating characteristics; the use of Unity3D software and socket communication technology to reproduce the actual application scene, to provide an immersive interactive experimental environment; through the design of experimental links such as equipment assembly and disassembly, control system wiring operation, real-time operation and control feedback, and time-limited points and questions, the experiment is more interesting. The application results demonstrate that the experiment effectively improves students' understanding and knowledge of FCU control design, control principles and energy saving strategies.