The invention discloses a dust detection device with low transmission loss. The dust detection device comprises a light transmitter, a light emitting pipeline, a light absorbing pipeline, a light guide stick and a photoelectric receiver, wherein the light transmitter is positioned at one end of the dust detection device and is suitable for transmitting a light beam to the light emitting pipeline; one end of the light emitting pipeline is connected with the light transmitter, and a gap through which dust and flue gas can pass is formed between the other end of the light emitting pipeline and the light absorbing pipeline; part of the light guide stick is positioned in the light absorbing pipeline, and one end face of the light guide stick is suitable for receiving light which is emitted by the light emitting pipeline and is scattered by the flue gas and the dust and transmitting the received light to the photoelectric receiver; the photoelectric receiver is positioned outside the light absorbing pipeline, is connected with the light guide stick along a radial direction, and is suitable for converting a light signal transmitted by the light guide stick into an electrical signal.