The invention relates to a pressure based method and device for detecting cigarette suction depth. The method comprises the following steps: detecting pressure in a cigarette suction channel when a smoker smokes a cigarette; determining suction depth of each suction action of the smoker according to the detected change of the pressure in the cigarette suction channel and corresponding time. The cigarette suction depth of the smoker is revealed by time and pressure for taking a puff on the cigarette, so that the amount of smoke produced by burning of tobacco raw materials and sucked by each puff of the smoker can be seen visually by the smoker and a cigarette worker. For the smoker, the smoker is helped to know own suction depth so as to be helped to correct own suction habits, and accordingly, harm caused by cigarette suction is avoided to the greatest extent. For the cigarette worker, suction depths of various smokers can be known, so that filling quantity of the tobacco raw materialsin cigarettes can be improved, and cigarette quality is improved.