Taking the soil of a relocation site in Shanghai as the research object, the effects of different soil conditioners on soil pH of the relocation site were studied through the combination of indoor simulation experiment and field empirical experiment, and the economic cost of soil conditioners was analyzed and evaluated. The results showed that the addition of soil conditioners such as ferrous sulfate, ammonium sulfate and potassium dihydrogen phosphate could reduce the soil pH in the relocation area, and the mixed application was more helpful to reduce the soil pH than the scattered application. Taking improved 1 m3 soil as an example, mixed application of 4 kg/m3 ferrous sulfate has a better effect on soil pH reduction. This study can provide technical support and guidance for landscape soil improvement in urban relocation sites.