The application belongs to the field of agricultural machinery, and discloses a seeder with automatic detection and reseeding functions, comprising a rack, seeding mechanism, a reseeding mechanism, acontrol device for determining whether the reseeding mechanism performs reseeding and a display mechanism for showing seeder operation parameters as well as reseeding amount, wherein the seeding mechanism is arranged on the rack, and the reseeding mechanism is arranged on the side of the rack opposite to the direction of the forward seeding direction of the seeding mechanism. The seeder realizes miss-seeding detection and compensation during seeding, and in addition, according to the signals of a photoelectric sensor as well as an encoder and the reseeding spacing, improves the seeding accuracy. Meanwhile, the detection is transmitted to a display device to facilitate intuitive understanding of the seeding status and make a corresponding judgment to improve the reliability of the seeder.