A special device for sowing sea cucumber seedlings at the bottom, belonging to the field of aquaculture devices, the device includes a seed playing funnel, a ventilation pipe, a seedling extension pipe, a seed positioning elbow and a ventilation handle; the seed playing funnel is a funnel The air pipe is a short pipe with a variable diameter tee and two short pipes in a horizontal straight line. The upper end of the air pipe is connected to the small diameter end of the seed playing funnel. Inserting interface, the ventilation handle is a hollow tubular structure, the ventilation handle is vertically connected with the ventilation pipe through the variable diameter insertion interface, the lower end opening of the ventilation pipe is connected with the extension pipe for planting seedlings, and the lower end of the extension pipe for seedlings is connected with the seedling positioning elbow. The device has the advantages of simple operation, accurate positioning, concentrated seed spreading, and high broadcasting efficiency. Good permeability, no wear and tear on seedlings and so on.