To study the planosol improving effect of subsoil mixing with different soil-improving materials, five treatments were implemented to investigate the physicochemical properties and the yield. The results showed that the subsoil layer physical properties was improved compared with the control. The soil water content was increased by 3.88%-7.78% in the 20-40 cm layer, and the hardness was reduced by about 50%. The soil permeability was increased and the soil three-phase ratio was improved. The solid phase was decreased by 9.71%-11.91%, liquid phase was increased by 1.24%-15.23%, and gas phase was increased by 4.50%-9.83%. The bulk density was reduced by 14.84%-16.77%, the subsoil layer nutrient contents were improved. The alkali-hydrolyzale nitrogen was increased by 8.24%-20.41%, the available phosphorus was increased by 38.89%-192.59%, the rapidly available potassium was increased by 13.22%-28.10%, and organic matter was increased by 33.84%-167.69%. The soil acidity was reduced with pH increased by 0.42 after lime treatment. The soybean yield was significantly increased by 13.00%-14.47%. In summary, subsoil mixing with soil-improving materials could provide technical support for the improvement of planosol and similar low-yield soils and for the increase in crop yield.