Abstract: In order to test the airtightness of cigarette packets efficiently and accurately, a nondestructive, rapid and accurate test method was developed based on dynamic pressure difference. The cigarette packet sample was put into a closed negative pressure system to let the air leak from the sample, and the variation of pressure in the closed system was recorded realtimely. The Bernoulli equation was used to deduce and fit the variation process of pressure, and the obtained effective leakage area was used to characterize the airtightness of the sample. The accuracy and repeatability of the developed method were tested. The results showed that: 1) In the case of testing a standard sample, the relative error between the test result and the actual leakage areas was less than 1.1% and the relative mean deviation was less than 2%. 2) The preferable testing conditions were test duration 7 seconds and the initial air pressure in the closed system -3100 Pa. 3) The coefficient of variation of the test results was less than 6%. 4) The correlation coefficient between the developed method and the current industry standard method was 0.987. This method provides a support for the rapid and nondestructive testing of airtightness of cigarette packets.