The walk-behind rice transplanter improves the work efficiency and quality of transplanting, realizes rationalized and dense planting, and is conducive to the mechanization of subsequent operations. Its principle of “taking the seedlings in successive divisions for direct planting” is as follows: the seedlings are neatly put into the seedling box in a group state, and move laterally with the seedling box, so that the seedling picker can take away a certain amount of seedlings in successive divisions. Under the action, the seedlings are inserted into the soil according to the agronomic requirements, and the seedling picker returns to the seedling box according to the trajectory to pick the seedlings.