Combining with the development of greenhouse industry, this article puts forward a design scheme of a control system of greenhouse based on the virtual instruments technology. The data measured by the sensors are sent to the computer through the data collecting card. It uses the LABVIEW which is virtual instrument software for programming. Through the graphical operation interface and display interface, the data of temperature, humidity, illumination intensity and co2 concentration can be acquitted, transmitted, analyzed and displayed timely. And it realizes the virtual intelligent control of greenhouse environment.