Abstract: Soil cement reinforcement technology has been frequently used for foundation treatment in the engineering development of beach reclamation area. The erosion of sea water could lead to the low shear strength of the reinforced soil and affect the curing effect. In order to analyze the influence of nickel-iron slag powder content on the shear strength of the soil-solidified soil under the conditions of difficult drainage and short construction period, an unconsolidated and undrained triaxial shear test was adopted. The results show that the content of nickel-iron slag powder has significant effects on the cohesion of cement-soil, while the internal friction angle is not significantly affected by the content of nickel-iron slag powder; in the maximum range of the content of nickel-iron slag powder. The internal cohesive force increases with the increase of the content of ferronickel slag powder, showing a unimodal trend. When the content exceeds 45%, it shows a downward trend. After 60 days of curing, the cohesive force of the ferronickel slag powder silt cement soil has reached. It can be judged that when the content of ferronickel slag powder is 45%, the ferronickel slag powder can play a better role in the cement soil, thereby enhancing the cohesion of the internal structure of the cement soil. The result has reference significance to the application of nickel-iron slag powder in electric power construction project and environmental protection.