Abstract: With the popularization and application of air conditioner, the comfort and energy saving of air-conditioning are the subjects that users are most concerned about. The principle of using millimeter wave radar to detect distance and angle was expoundes, and combines the application scenarios of air conditioning. The millimeter wave radar intelligently detects the distance, the left and right angles of the human body from the air conditioner, and the specific number of people. The air conditioner performs directional air supply control and runs the energy-saving mode.It not only ensures the user's comfort when using the air conditioner, but also achieves the energy-saving effect.

Key words: Millimeter wave radar, Directional air supply, Detection, Energy saving