According to thermal comfort and energy conservation of trailer house, it analyzes the heat transfer characteristics about envelop enclosure of trailer house in cold regions. And it is got by the method of non-steady state heat conduction from two aspects, that is, the heat conduction and heat storage of envelop enclosure. It gets the method to calculate heat load of envelop enclosure and the conclusion that the vacuum insulation panel located inside the enclosure of house is more suitable in cold regions.