The invention relates to a seedling picking and planting device for a transplanter, belonging to the technical field of agricultural machines. The seedling picking and planting device comprises a frame, a conveyer belt used for conveying seedlings and a chain type planting unit located at the front end of the conveyer belt, wherein the chain type planting unit comprises a motor-driven chain type transmission unit and a plurality of dibble-type duck-billed planters arranged on the chain type transmission unit; an air compressor drives a cylinder to move through a reversing valve; the frame is provided with a shift fork; the shift fork can rotate under the driving of the cylinder, so the shift fork has two operation modes, i.e., a seedling blocking mode and a seedling releasing mode; the frame is provided with an arch bar hinged with the frame; and the arch bar is divided into two sections by the hinge joint of the frame and the arch bar, the first section of the arch bar is matched withthe moving trajectories of the planters, and the second section of the arch bar is a switch rod piece matching with the spring contact of the reversing valve. The seedling picking and planting deviceof the invention is simple and reliable in structure and has high seedling picking accuracy.