Test device and test method for crack evolution and seepage characteristic of gas-containing shale

A test device and a test method for crack evolution and seepage characteristic of gas-containing shale. The test device and the test method belong to the technical fields of rock engineering and unconventional natural gas engineering. The device includes a three-shaft pressure chamber, a bias pressure loading system, a hydrostatic pressure loading system, an upper-end fluid system, a lower-end fluid system, a vacuumizing system, a constant temperature system, and a data control and acquisition system. According to the test method, a strain gauge is replaced by a displacement sensor so that problem of leakage of oil and gas caused by wires of the strain gauge is solved. Circular displacement sensors are arranged respectively on an upper part, a middle part and a lower part of a sample so that crack growing situations at different positions of the sample can be detected. Deformation of the whole sample is detected through an axial displacement sensor. According to a reference standard of the crack evolution and the seepage characteristic in a cracking process of a gas-containing shale sample and a reference standard of the whole crack evolution of the cracking process of a gas-containing shale sample, a crack evolution state in the cracking process of a gas-containing shale sample is analyzed and variation trend of a whole crack in the cracking process of the gas-containing shale sample is determined.