The different tillage depth of red soil slope farmland has an important effect on the quality of ploughing layer and crop yield. From the point of view of soil properties, the vertical depth soil moisture, bulk density, porosity, soil compactness, soil shear strength and soil organic matter under different tillage depth treatments in red soil slope cultivated land were studied in Jiangxi Province. Available phosphorus and available potassium were also analyzed. The results showed that:(1) The effects of different tillage depth on soil porosity, saturated water content and field water holding capacity were no tillage < tillage 20 cm < tillage 10 cm < conventional tillage < tillage 30 cm, the effect on bulk density was tillage 30 cm < conventional tillage < tillage 10 cm < no tillage < tillage 20 cm; compared with the conventional tillage, the soil saturated water content, field water holding capacity and soil porosity were increased by 18.17%, 12.67% and 5.94%, respectively after 30 cm tillage. Soil bulk density decreased 6.90%. (2) The soil compactness under different tillage depths was tillage 30 cm < tillage 10 cm < tillage 20 cm < no tillage < conventional tillage; soil shear strength was tillage 30 cm < conventional tillage < conventional tillage 10 cm < no tillage 20 cm. Compared with the conventional tillage, ploughing for 30 cm reduced soil compactness and shear strength by 27.07% and 24.82%, respectively. (3) The average content of soil organic matter was the highest under 20 cm tillage (13.48 g/kg), and lowest under no tillage treatment (9.39 g/kg). Soil available nutrients were mainly distributed in 0-20 cm soil layer. Compared with the no tillage treatment, soil available nutrients contents increased under the tillage treatments, among which tillage 20 cm and conventional tillage gave the significant differences. (4) The results of principal component analysis showed that the treatment of tillage 30 cm had the best effect on the comprehensive improvement of soil properties in red soil slope cultivated land. These results could provide reference for the improvement of ploughing layer soil and the construction of rational tillage layer in slope cultivated land of red soil.