The invention provides a false triaxial high-pressure permeation tester, belongs to the technical field of geotechnical engineering, and is suitable for testing of permeation and salt filtration capacities of consolidated and unconsolidated rock and soil, especially an unconsolidated plastic viscous undisturbed soil sample. The undisturbed soil sample is used as a test soil sample, a false triaxial principle is utilized, the undisturbed soil sample is externally sleevedly provided with a flexible silicon rubber casing pipe, the outer side of the flexible silicon rubber casing pipe is sleevedly provided with a perforated sleeve for supporting the undisturbed soil sample, a confining pressure hole formed in a side wall applies confining pressure to the undisturbed soil sample, when the confining pressure is greater than a shaft pressure, high-pressure water flow only can pass through the interior of the undisturbed soil sample and is not leaked from a joint face of the undisturbed soil sample with a sealing material, so as to achieve the sealing effect at high pressure; an upper top cover and a lower base are connected with the side wall through screws, and thus deformation caused in a process of filling or placing the undisturbed soil sample can be avoided. The tester is simple in structure, can simulate actual conditions of an underground water-bearing system, and can effectively solve the problem of permeability testing of the high-pressure undisturbed soil sample.