The invention belongs to the field of deep high-temperature and high-pressure oil and gas exploitation rock mechanical testing, and particularly relates to a gas
permeation testing method in low-permeability rock time-dependent deformation under the action of thermal-gas-mecha-nical
coupling. The method includes the following steps that a
rock core test piece is installed into a clamp holder, and the leakproofness of gas
permeation testing is checked; the confining pressure, the temperature, the air pressure and the
axial pressure are sequentially applied to a triaxial
cell to predetermined values; the pressure of a
high air pressure tank is increased instantaneously, the gas
permeation parameters in the time state are calculated, and accordingly the rock gas permeation rate existing when the numerical value of a low air pressure tank is equal to the numerical value of the
high air pressure tank is calculated; the
gas pressure is adjusted to an initial value, the gas permeation rates at other moments are determined, and the gas permeation rates are given to a computer for drawing output. By the adoption of the method, the gas permeability of low-permeability rock under different time-dependent scales can be determined, the relation among the permeability parameter, the temperature parameter, the
time parameter, the stress parameter and the strain parameter can be drawn automatically through a
computer program, data result errors caused by not taking multi-field
coupling and time-dependent factors into account in an existing device are avoided, and measurement accuracy is improved.