The utility model discloses a seeding device of a tobacco floating seedling raising tray, which comprises a seedling raising tray conveying mechanism, a first substrate blanking hopper, a first substrate scraping mechanism, a first hole pressing mechanism, a second substrate blanking hopper, a second substrate scraping mechanism and a hole pressing and seeding integrated mechanism are sequentiallydistributed along the conveying mechanism, and the first hole pressing mechanism adopts a tray type structure; the hole pressing and seed sowing integrated mechanism is used for screening seeds and then feeding the seeds into the material distribution disc, and the seeds are discharged one by one through three layers of staggered plate bodies of the material distribution disc; and secondary holepressing and seeding are simultaneously completed through the combined conical hole pressing seeding hopper and the round-head hole pressing rod. The forming of the seed holes is fully guaranteed by means of two times of matrix filling and hole pressing; the hole pressing and sowing integrated mechanism ensures that the sowing position is proper, the device works reliably and durably, it is ensured that the sowing success rate can reach 195/200, thinning operation does not need to be conducted any more, the sowing quality is improved, and the seedling forming quality of tobacco seedlings is ensured.