The invention relates to a cigarette packaging sealing degree detecting device and method. The cigarette packaging sealing degree detecting device comprises a chamber, a ventilation duct, a pressure sensor, a vacuum generating device, and a flow meter; the chamber is configured to form a sealed space, and the interior of the chamber is used for placing a cigarette package to be tested; a first endof the ventilation duct is used for communicating with the interior of the cigarette package to be tested, the junction with the cigarette package to be tested is configured to form a seal, and a second end is located outside the chamber; the pressure sensor is used for detecting the pressure in the chamber; the vacuum generating device is connected to the chamber, and is used for adjusting and maintaining the pressure in the chamber within a preset pressure range according to the pressure value detected by the pressure sensor; and the flow meter is arranged on the pipeline connecting the vacuum generating device and the chamber, and is used for displaying the flow value in the pipeline, so as to judge the sealing degree of the cigarette package to be tested according to the flow value when the pressure in the chamber is within the preset pressure range. The invention has clear detection index and high accuracy, and is used for alleviating the influence of the poor sealing degree of the cigarette package on the quality of the cigarette.