In order to ensure the sealing function of expandable liners in φ120mm boreholes, based on the proper design of an “8” shape section corrugated pipe, the hydrodynamic expansion forming process of the corrugated pipe with different wall thickness and materials is simulated by using the finite element theory, and the indoor hydrodynamic expansion test is carried out. Under the condition of satisfying the extrusion strength and internal pressure strength, the thinner the wall thickness of liners, the better the expansion effect; the “8” shape section liners suitable for 120 mm boreholes should meet the following conditions: yield ratio≤0.6, elongation≥25%, tensile strength σb≥410MPa; the minimum diameter of the liners after expansion can meet the requirements of subsequent mechanical expansion, and the maximum expansion pressure is 13.6MPa, which meets the requirements of drilling site operation. This provides technical support for field test of the liners.