The barrier performance of cigarette packaging plays a key role in the quality consistency of cigarette products. In order to study the influence of multi-layer packaging on the moisture barrier in a dry environment, an automatic dynamic moisture analysis climate chamber was developed to investigate the moisture diffusion process through different packaging materials under specific temperature and humidity conditions. A moisture barrier index was used to characterize the moisture barrier performance quantitatively. The results showed that: the evaluation method for moisture barrier performance of multi-layer packaging of cigarette packets could accurately quantify and characterize the moisture barrier performance of the packaging, and the model calculation values were consistent with experimental values. Under low humidity conditions, the amount of moisture permeating through the clearance between layers and the materials of different layers of the cigarette pack was different. For BOPP films, moisture mainly diffused through the film. For different labels and inner liners, the distribution ratios of moisture diffusion through the material and the clearances were different. The moisture barrier of BOPP films was the key factor influencing the moisture consistency of cigarettes. The moisture barrier performance of hard packets was better than that of soft packets. The moisture diffusion processes of cigarettes in different packets were predicted accurately. In this paper, a moisture barrier test and evaluation method for multi-layer cigarette packaging was established. The moisture barrier performance of each layer and different parts of each layer of cigarette packets was quantitatively characterized and the key factors affecting the moisture consistency of cigarettes in packets were identified. Moreover, the prediction of moisture content in cigarettes within different packets in a known environment was realized.