This paper presents the design of a smart household environment illumination dimming-control. The control can be operated using either an Android App or a computer using either Wi-Fi or Zigbee to connect to a Database Management System (DBMS). The DBMS can synchronize with a central controller in order to achieve simple and convenient dimming-control of the user's home illumination. In this paper, a linear dimming scheme was adopted to reduce the light gleaming. In order to achieve suitable variations in the illumination environment, a highly-efficient three-color LED was used as the light source. This paper covers the designs of six environment illumination controls for users who can deliver the control states to the central controller and mobile phone. A 24 V DC power supply was designed in this system and can collocate with the DC/DC converter to form a power module suitable for general home use. The interface of the proposed environment illumination control is clear and simple; one can verify that the design presented in this paper possesses very high practicability from the experimental results.