In order to study the effect of sodium sulfate solution on the shear strength of cemented soil, direct shear with unconsolidated-undrained test was carried out on sodium sulfate corrosion of cemented soil. The test results show that the shear strength of cemented soil gradually decreases with the increase of sodium sulfate solution concentration, and angle of internal friction and cohesion of the shear strength index gradually decrease. When the concentration of sodium sulfate solution is constant, the shear strength of cemented soil gradually decreases with the increase of sodium sulfate solution corrosion time, and cohesion of the shear strength index gradually decreases. The corrosion has a great impact on cohesion, while it has little effect on angle of internal friction.