Abstract. In order to satisfy the design requirements of diversified seedling transplanting mechanisms, this paper carried out systematic research on the creation method of planetary gear train mechanisms for transplanting based on the graph theory and the structural and functional characteristics of the transplanting gear train so as to establish a complete configuration atlas of a transplanting gear train. The structure and transmission ratio constraints of the planetary gear train for transplanting are established on the basis of the displacement graph of the planetary gear train. Selection methods for the planetary gear train rack, input, and output components are also proposed. The classification of three types of planetary gear trains is introduced by analysing the motion characteristics of the seedling transplanting mechanism, which realizes the systematic screening and classification of the double planet carrier gear train (DPGT) configuration. A total of 528 DPGTs, which are suitable for transplanting, including 3 five-bar, 13 six-bar, 92 seven-bar, and 420 eight-bar DPGTs are obtained. The problem of the single planet carrier transplanting mechanism not satisfying the requirements of a diversified transplanting trajectory is solved.