## 1 Introduction  
Many engineering construction and scientific research fields are related to the permeability of rock mass, such as hydraulic engineering, civil engineering construction, petroleum exploitation and underground storage, disposal of nuclear wastes, environmental pollution, carbon dioxide storage and underground thermal motion, etc. [1; 2; 3; 4; 5; 6]. The permeability of the rock mass mainly depends on the fracture permeability. The key problem of quantitatively evaluating the anisotropic rock permeability includes correctly and effectively determining the fracture permeability. The permeability of anisotropic fractured rock (e.g., permeability coefficient, equivalent permeability coefficient and the permeability coefficient tensor of the rock mass) is the most important parameter for engineering design, construction and running. Moreover, it is needed to quantitatively determine the anisotropic rock permeability to study the engineering structure, foundation and groundwater, and the stress field, temperature field, seepage field and chemical field coupling. The methods to determine the anisotropy permeability coefficient of fractured rock include the following: the fracture sample method, the pumping test method [7; 8; 9; 10; 11; 12], the three section of water pressure test method [13], the cross-hole water pressure test method and the method of numerical inversion. All of these methods either depend on the strict hydrogeological conditions that are demanding, time-consuming and troublesome, with a high test cost, or have theoretical flaws, which are difficult to apply practically. For example, petroleum exploitation and nuclear waste treatment projects must deal with deep buried aquifer and weak permeability rocks, which mean it is very difficult to conduct the pumping test. Hence, it is necessary to put forward a theoretical time-saving and easy to operate method to investigate the hydrological parameters of these particular projects. Recently, the slug test has been widely used in determining the aquifer permeability parameters. In 1967, [PERSON] [14] proposed the theory and method of fitting the standard curve with the semi-logarithmic graph of water level changes in the well that was dimensionless with regard to time to obtain the permeability coefficient. [PERSON] and [PERSON] [15] supposed that the groundwater head has the constant head boundary in a certain range, and the boundaries remained constant during the test, without considering the effect of well-skin, according to the ratio of screen length and casing radius to fit the standard curve, and obtained an effective influence radius under test conditions, according to the gradient of the change in well water level with time on the semi-logarithmic graph curve to calculate the permeability coefficient. [PERSON] [16] assumed that the aquifer is equal thickness, homogeneous and isotropic, which provided a strict physical theory for the research of underdamping and overdamping aquifer, and protracted a series of standard curve, made a semi-logarithmic graph curve by the dimensionless drawdown and time to fit the standard curve to calculate the permeability coefficient. [PERSON] [17] proposed a numerical solution method to analyze the influence of aquifer anisotropy on the results of the slug test. [PERSON] [18] used the high-resolution slug test and provided a detailed vertical distribution of the permeability coefficient. [PERSON] [19,20] developed a field quick testing system for determining rock and soil permeability coefficients based on the principle of vibration of water flow movement in a single well, which made it possible to test rock and soil permeability coefficients in the field fast and efficiently. [PERSON] [21] applied the sectional slug test in a field to measure the aquifer permeability and verified the probability to determine the aquifer permeability by the sectional slug test. Meantime, the research used wavelet technology to reduce the noise of the slug test field data.