The utility model discloses a high-humidity low-concentration flue dust sampling pipe which is characterized by comprising a sampling head, a sampling pipe, a heating tape, a temperature sensor, a processing unit and a rear seat, wherein the sampling head is connected with the sampling pipe; the sampling pipe comprises a pitot tube and a backflow prevention heating device; a protective tube is arranged outside the sampling pipe; the heating tape winds the outer wall of the sampling pipe; the temperature sensor is arranged between the heating tape and the sampling pipe and is connected with the processing unit; a signal output by the temperature sensor is transmitted to a singlechip microcomputer to be processed. According to the utility model, the sampling pipe and a heating control system are integrated together, overall heating is carried out, and the flue dust sampling pipe is small in overall size and convenient to carry; with a heating drying device and a condensate water backflow prevention device, heating can be controlled while backflow is prevented, and thus normal sample collection can be carried out in a high-humidity low-concentration environment; the flue dust sampling pipe is high in intelligence degree and is suitable for more working conditions and environments.