The invention discloses a contactless heart rate detection device comprising a detection unit, a frequency mixer, an amplification unit, a preprocessing unit, a conversion unit and a display unit. The detection unit is used for detecting life parameters; the frequency mixer is used for receiving signals of the detected life parameters; the amplification unit is connected with the frequency mixer and used for amplifying the signals of the life parameters; the preprocessing unit is connected with the amplification unit and used for processing the amplified signals of the life parameters; the conversion unit is connected with the preprocessing unit and used for converting the signals of the life parameters into digital signals; the display unit is used for displaying the digital signals. The contactless heart rate detection device has the advantage that the purpose that a sauna room can be automatically opened and closed through the heart rate is achieved by measuring the heart rate of human bodies through the contactless device and using the device with the sauna room cooperatively.