The invention relates to a control system acting on greenhouse plant growth. The control system comprises a PLC, an environment sensing system, an environment regulating system, a data storage unit, and an HMI user interface for man-machine interaction and system information real-time observation, wherein the environment sensing system, the environment regulating system, the data storage unit and the HMI user interface are connected with the PLC. The control system has the following advantages that the distribution ratio of red and blue light relative spectrums can be reasonably regulated according to different plant attributes and different requirements on illumination; temperature, humidity, light and carbon dioxide content level intelligent acquiring, sensing and regulating are integrated, and intelligent management is achieved; distribution of drip irrigation systems and distribution of LED light source relative spectrums can be adjusted, and energy saving and environmental friendliness are achieved; greenhouse inside and outside environments are monitored in a unified mode through a environment light sensor, greenhouse outside environment light is utilized, the greenhouse outside environment light is monitored, and management of greenhouse inside environment light is finer.