A tent can be regarded as one kind of special building or man-made space, which is widely used for the wild living, nomadic living and disaster relief. The envelop enclosure of tent is formed by fabric layer, which has very thin thickness of 0.5-2 mm and high air permeability and thermal radiation adsorption. Accordingly, its indoor thermal environment is very poor in most cases, as a result of low thermal inertia and resistance of tent envelope. For improving thermal environment of tent, new type structure was proposed and applied in tent, including outer fabric layer, phase material (PCM) layer and inner fabric layer. Meanwhile, theoretical model depicting heat transfer of this new type structure used in tent was established and verified. Moreover, for the climatic conditions of Chengdu city in China, the thermal performance of composite three layers structure of tent were evaluated with the aid of numerical simulation under the influence of different PCM thermo-physical properties, containing PCM thermal conductivity coefficient, latent heat, specific heat capacity and phase-transition temperature. Low PCM thermal conductivity coefficient and phase-transition temperature, high phase change latent heat and specific heat capacity are needed to achieve the excellent thermal performance of new type structure.