In order to discuss the influence of different subsoiling methods on root morphology and tobacco-curing characteristics of mountain tobacco, verify the actual effect of the new-type subsoiling shovel independently designed, and seek excellent measures for cultivating mountain tobacco, field tests were carried out by setting three treatments: improved subsoiling (NS), traditional subsoiling (TS) and no subsoiling (CK). The results showed that compared with traditional chisel-type subsoiling shovel, the soil disturbance coefficient was increased by 14.79 percentage points, the soil compactness was decreased by 53.95% and the change rate of soil bulk density was increased by 5.84% at 30cm underground after tillage. Compared with traditional subsoiling, the total root length, root surface area, root volume, plant height, stem circumference, leaf area index, maximum leaf length, maximum leaf width, underground dry matter weight, aboveground dry matter weight, yield and upper leaves of planted tobacco were increased by 33.80%, 30.41%, 45.67%, 18.36%, 10.72%, 16.53%, 4.02%, 2.15%, 28.26%, 18.28%, 6.43% and 4.11%, respectively at the early stage of maturity，the number of effective leaves increased by one leaf, the average price and output value was increased by 4.83% and 11.63%, respectively, while the above indexes were significantly improved compared with the control group without subsoiling operation. It was found that subsoiling can effectively improve the tillage structure of mountain tobacco fields in Yunnan Province, thus promoting the root growth of mountain tobacco, enabling the root to absorb more water and nutrients for the above-ground development, improving the dry matter weight of tobacco leaves and the economic performance. Independently designed type subsoiling spade and its supporting carrying machine had more remarkable effect on subsoiling operation in middle Yunnan Province.