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In view of the cumbersome procedures, high agronomic requirements, high workload, low efficiency and lack of special machines in the seed-plot preparation stage of cigar tobacco planting in China, the existing seed-plot preparation machines for other crops were mainly designed for sandy loam soil and mostly used passive ridging, which had poor ridging effect under clay soil conditions in the cigar tobacco growing areas of China. Combining the root growth characteristics of cigar tobacco with the agronomic requirements of the seed-plot, the cigar tobacco adjustable seed-plot ridging and film spreading machine was designed, which can realize the integrated operation of rotary tillage, deep fertilization, ridging, film spreading and film edge mulching. According to the principle of ridging forming and ridging shape requirements, the operating parameters of rotary tillage were determined, the structural design and mechanical analysis of the shaping roller were made, the principle of seed-plot height adjustment was explained, the speed relationship between the speed of the machine, rotary tillage device and shaping roller was matched, and the structure and operating parameters of the edge pressing wheel and the mulching disc were analyzed and determined by combining the conditions of film breakage and the factors affecting the film edge mulching. The field experiment showed that the average ridge height, bottom width, ridge distance and furrow width were 277.4mm, 701.8mm, 1230.2mm and 514.4mm,respectively, and the stability coefficients of ridge height, bottom width, ridge distance and furrow width were more than 94%;the average film edge mulching widths were 71.7mm and 75.6mm under two working conditions, and the stability coefficients were 88.87% and 87.00%. All the experimental indicators met the requirements of cigar tobacco growing.