The permeability transformation between the laboratory and formation condition is an important research in reservoir engineering.The compression of the rock will lead to the decrease of the pore size and the permeability reduction，which results in the problem that the permeability of rocks measured at laboratory condition is higher than that at reservoir condition.Therefore，it is necessary to do the conversion calculation of permeability from laboratory condition to the reservoir one.According to the difference stress state between laboratory and reservoir，a study was conducted in this paper about the conversion method of laboratory permeability to reservoir condition.The conversion formula presented in this paper utilizes the three dimensional stresses to overcome the problem taken from using the overburden pressure only.The case calculation result shows that the reservoir permeability calculated with overburden pressure only is quite smaller than that with three dimensional stresses.Meantime，the conclusion can be draw that the low permeability from the new method is about 10% larger than the initial method.