The invention discloses a seeding device of a tobacco floating seedling raising plate. The seeding device comprises a conveying mechanism of the seedling raising plate, and a first substrate discharging hopper, a first substrate scraping mechanism, a first indenting mechanism, a second substrate discharging hopper, a second substrate scraping mechanism and an indenting and seeding integrated mechanism which are sequentially distributed along the conveying mechanism; the first indenting mechanism adopts a disc type structure; the indenting and seeding integrated mechanism is used for screeningseeds and then conveying the seeds into a material dividing plate, and the seeds are discharged one by one through three layers of staggered plates of the material dividing plate; then secondary indenting and seeding are completed at the same time through a combined conical indenting seeding hopper and a round-head indenting bar. Two times of substrate filling and indenting fully guarantee formingof seed pits; the indenting and seeding integrated mechanism guarantees that the seeding positions are proper, the device is reliable and lasting in work, it is guaranteed that the seeding success rate can reach 195/200, thinning is not needed, the seeding quality is improved, and the seedling quality of tobacco seedlings is ensured.