wherein the pressure bearing device comprises a piston, an upper flange, first and second pressure heads, first and second porous water-permeable steel plates, a pressure bearing cylinder, and a base, a top and a bottom of the pressure bearing cylinder are fixedly connected to the upper flange and the base, respectively, a water-permeable stone cylinder is arranged in an inner cavity of the pressure bearing cylinder, a sample is placed in the inner cavity of the pressure bearing cylinder, the sample is placed in the water-permeable stone cylinder, the first and second porous water-permeable steel plates and the first and second pressure heads are arranged on a top and a bottom of the sample, respectively, the first pressure head is connected to a bottom of the piston and is configured to apply pressure to the first porous water-permeable steel plate, the water-permeable stone cylinder is isolated from hydraulic oil through an isolation film, and a hydraulic jack is arranged on a top of the piston;

the confining pressure application device comprises a manual pump, a first energy accumulator, a three-way valve, and two pressure gauges, the two pressure gauges are a first pressure gauge and a second pressure gauge respectively, hydraulic oil in an oil tank is pressure-applied sequentially through the manual pump and the first energy accumulator via a pipeline, a first valve and a first one-way valve are sequentially connected in series between the manual pump and the first energy accumulator, the pressure-applied hydraulic oil is connected to a hydraulic oil inlet channel on the base through an oil outlet end of the first energy accumulator, a second valve, the first pressure gauge, a right-port- and a lower-port of the three-way valve, a hydraulic oil outlet channel is formed on the upper flange, a third valve is mounted at the hydraulic oil outlet channel, and the hydraulic oil flowing out from the upper flange flows through the hydraulic oil outlet channel, the third valve, the second pressure gauge and the three-way valve and then flows back again to participate in pressure application and circulation of the hydraulic oil in the confining pressure application;

the seepage pressure application device comprises a water pump group and a second energy accumulator, a corrosion solution in a corrosion-resistant water tank flows through a filter element, then the corrosion solution is pressure-applied and pumped by the water pump group and sequentially flows through a fourth valve, a second one-way valve, a third pressure gauge and a fifth valve to enter the second energy accumulator, the corrosion solution pressure-applied and stabilized by the second energy accumulator flows through a fourth pressure gauge, then flows in from a corrosion solution inlet channel on the base, flows through the second pressure head at a lower part and the solution flow channel inside the second porous water-permeable steel plate, and flows in the water-permeable stone cylinder to be continuously accumulated; meanwhile, the corrosion solution corrodes a side surface of the sample until the corrosion solution is fully accumulated, and finally flows out from a corrosion solution outlet channel on the piston through the first porous water-permeable steel plate at the upper part of the pressure bearing device, the first pressure head at the upper part, and the piston, and the corrosion solution outlet channel is connected to a fifth pressure gauge;

the seepage pressure application device further comprises a vacuum device, the vacuum device is provided at a corrosion solution flow outlet, the vacuum device is used to extract the corrosion solution when the corrosion solution is difficult to flow out, and an empty corrosion-resistant water tank is adopted to collect waste liquid after corrosion.