In order to realize the stability and high efficiency of seedling taking and throwing of vegetable transplanter, a fully automatic seedling taking and throwing device based on a combined struture of crank rocker and guide rail was designed according to the seedling taking and throwing mode of bowl. The seedling taking and feeding device cooperated with the tray feeding device, seedling guiding device and seedling sorting device to complete the independent tray feeding, seedling taking, seedling throwing and seedling sorting. The structural parameters of rocker-rail and crank rocker in seedling feeding device were designed by analytic method, and the movement process of seedling feeding device was calculated and analyzed by vector equation method and ADAMS simulation, and the actual movement track of seedling feeding device taken by high-speed camera was compared with simulation result, which verified the correctness and feasibility of the design. Taking pepper bowl seedling as test object, seedling speed, plant height and matrix moisture content were selected as test factors, and orthogonal test was carried out with seedling success rate, seedling injury rate, seedling throwing success rate and success rate of planting as evaluation indexes. The results of the experiment showed that under the given factor level, when the single row of the whole machine seedling taking and throwing speed was 90 plants/min, the seedling height was 110mm and the matrix moisture content was 50%, the seedling picking and throwing effect was the best. The seedling taking success rate was 95.14%, the damage seedling rate was 1.39%, the seedling throwing success rate was 93.05% and the success rate of planting was 91.67%.