Rapeseed is the most important oil crops in China. Rapeseed seedling transplantation is a chief cultivation pattern in the crop rotation area of rice and rapeseed. The existing transplanter took the soil mobility as a prerequisite for transplanting, which was not suitable for the sticky soil of rice stubble field. In addition, the working efficiency of transplanter was low. In order to improve the present situation of rapeseed mechanized transplanting, a 2ZY-6 type rapeseed carpet seedling transplanter which could finish ditching, transplanting and compacting all at once was designed with the reference principle of the rice transplanter. The efficiency of the rapeseed carpet seedling transplanter could reach up to 10 times higher than that of a traditional rapeseed transplanter. The rapeseed carpet seedling transplanter got rid of the limitation of soil mobility and had strong ability to adapt the soil environment of paddy stubble field. Rapeseed carpet seedling transplanter consisted of a furrow opener, seedling feeder mechanism, planting mechanism and compacting mechanism. The furrow opener adopted the design of corrugated disc. The stubble breaking ability was strong and the furrow type was stable which was beneficial to the subsequent planting of seedlings into the gap. The mechanical hydraulic copying mechanism was designed to control the planting depth under the condition of uneven soil. The Vshaped compacting mechanism was designed, and the suppressing wheel which adopted the V type symmetrically to arrange through a longitudinal deflection angle was used to cut the soil at the sharp angle and push the soil at side direction. The soil on both sides of the seedling ditch was squeezed around the seedling through the suppressing wheel, and the seedlings were compacted and kept upright. At the same time, the key components and parameters of the planting system were optimized according to the agronomic requirements of rapeseed transplanting, and the requirements of large area and the low number of cutting block and picking seedling of rapeseed carpet seedling were realized. The performance test of the rapeseed carpet seedling transplanter was carried out under the paddy soil and dry stubble soil. The test results showed that the transplanting effect was outstanding when the moisture content of paddy soil was 25%~30%, and the average transplanting qualified rate was up to 85.66%. The best transplanting quality was obtained in dry stubble field when the moisture content of dry stubble soil was 17.6%~26.8%, and the highest transplanting qualified rate was 87.01%. The transplanting speed of paddy soil should be kept within 1.15m/s, and the transplanting speed of dry stubble soil should be kept within 0.8~1.2m/s, which can directly satisfy the requirements of rapeseed transplanting agronomy. This study provided a reference for users to use rapeseed carpet seedling transplanter and select suitable transplanting conditions. 