Abstract: Taking shajiang black soil as the test material, the effect of peat, sand, and superphosphate as soil amendments on soil compressive strength was studied by response surface methodology, the relationship between soil compressive strength and soil physicochemical properties was analyzed, in order to provide reference for soil amelioration in the shajiang black soil area.The results showed that the primary and secondary order of the effect of amendments on reducing soil compressive strength was peat＞sand＞superphosphate, and the compressive strength was highly significantly positively correlated with the clay content and significantly positively correlated with the unit weight.There was a highly significant negative correlation with sand and the content of organic matter, and a significant negative correlation with porosity.According to the optimal solution provided by Design Expert 12,the addition of peat 77.72 g·kg^-1,sand 61.91 g·kg^-1,and superphosphate 2.63 g·kg^-1 effectively improved the soil physical and chemical properties(bulk density,（1.24±0.03）g·cm^-3;porosity, 53.01%±2.36%;clay, 24.8%±0.64%;silty sand, 38.37%±1.22%;grit, 36.83%±1.51%).In the end, the minimum compressive strength of the soil was 266.67 kPa, which was 53.62% lower than the compressive strength of the control treatment.There was a excellent effect on land preparation after effectively reducing the soil compressive.