Seeder depth limiting mechanism and seeder

The utility model discloses a depth limiting mechanism of a seeding machine. The depth limiting mechanism comprises a connecting seat which is fixed on the seeding machine and extends to the ground, aditching disc, a seeding pipe and a press wheel which are fixed on the connecting seat and are sequentially arranged along the seeding direction, and a depth limiting plate and a depth limiting adjusting piece which are connected to the connecting seat, and the depth limiting adjusting piece is used for adjusting the depth limiting depth of the depth limiting plate. The utility model further discloses a seeding machine which comprises a main beam, a plurality of seeding machine depth limiting mechanisms fixed on the main beam, and a linkage piece used for adjusting the corresponding depth limiting plates in a linkage manner. By arranging the depth limiting plate, the ditching width and depth can be limited; in addition, the distance between the lower edge of the depth limiting plate and the lower edge of the ditc