Extruded-puffed foods absorb moisture extremely easily from environment to cause losing their unique texture characteristic of crispness. The knowledge of the moisture absorption kinetics can help to select proper package materials and storage conditions. Four kinds shape of millet extruded-puffed foods were allowed to absorb moisture from air with different relative humidity levels at different temperatures, and the processes were simulated. Compared with the Peleg and diffusion models, the Weibull model was more suitable for predicting water absorption behavior of millet extruded-puffed foods. At the same temperature, the initial water-absorbing rate approximately linearly increased with the relative humidity of air. At the same relative humidity, the general water-absorbing rate approximately linearly increased with temperature. The lower the temperature was, the higher the relative humidity and equilibrium moisture were. There were little differences in equilibrium moisture between the four samples, while significant differences in water-absorbing rates especially at lower temperature combined with lower relative humidity. The different external layer with pore structure of each sample were possibly the main reason of the various initial water-absorbing rates