In view of the fact that the hygrotherml properties of humidity control materials determine their heat and moisture transfer behavior， two new palygorskite-based composite humidity control materials， namely palygorskite based flax fiber material （FP） and palygorskite based wood fiber material （WFP） were developed. The water vapor permeability coefficient， isothermal adsorption curve， moisture diffusivity and other physical parameters related to the moisture absorption and release capacity and heat and humidity transfer characteristics of two materials were measured. The influence of humidity control material thickness and upper and lower limits of relative humidity on the moisture buffer value were explored. The results show that the thicker the composite humidity control material， the higher the relative humidity range， the stronger its moisture absorption and desorption ability. The moisture buffer values of FP and WFP with a thickness of 2.5 cm reach 2.83，3.11 g/（m²·%）， respectively.