The planting arm of the direct-taking wide-narrow row splitting mechanism belongs to agricultural machinery; the planting arm includes a planting arm shell and a cam fitted on the planting arm shell, a shift fork shaft, a shift fork, a seedling pusher and a seedling claw, and the cam The cam axis and the shifting fork axis of the shifting fork shaft are arranged in a space staggered angle, through the space staggered angle, the pusher bar and the seedling claws are perpendicular to the rice transplanter seedling door, and the pusher bar and the seedling claws are aligned with each other. The working direction of the rice transplanter is parallel; the planting arm realizes the operation of wide and narrow rows to form rectangular seedling blocks when picking seedlings, and the two sides of the claws act on the seedling blocks at the same time, and the seedlings are vertical when transplanting. The structure is simple and reasonable, and the operation quality is good. features.