The invention provides a correction method for an unsaturated soil soil-water characteristic curve based on axis translation technique test. The method comprises the steps of: selecting micropores with pore size of 0.003-0.3 mum in non-saturated soil; idealizing the micropores with one open end and one closed end into an equal-diameter or unequal-diameter capillary diameter model with one open end and one closed end; establishing a relation between matric suction and gas volume of pores in unsaturated soil; in a compression process of the gas in the pores, filling the gas volume compression part with pore water in the soil, namely the volume filled with pore water equals to the amount of compression of the gas volume; establishing a relation between the pore water filling volume and matric suction to obtain a corrected relation between the moisture content and matric suction and establishing a correction formula; and calculating the soil-water characteristic curve based on axis translation technique. The invention has the beneficial effect that the method can improve the accuracy of the axis translation technique in test of unsaturated soil-water characteristic curve, so that the tested soil-water characteristic curve is closer to the real result.