Seeder with middle ditching, unit profile modeling and seeding depth adjusting functions

The invention discloses a seeder with middle ditching, unit profile modeling and seeding depth adjusting functions, belonging to the field of rotary tillage seeders. The seeder mainly comprises a frame, a rotary tillage transmission device, a rotary tillage mechanism, a middle ditching mechanism, a seed-metering transmission mechanism, a seeding unit and a seeding amount electric control system. The operations of rotary tillage, middle ditching and seeding can be finished at a time. During operation, power of a tractor is transmitted to a rotary tillage cutter shaft and a ditching cutter shaft through a universal joint, a gearbox, a rotary tillage transmission shaft and a gear case, rotary tillage and ditching are performed, and the ditch wall is smooth through a breast board, a ditch cleaning shovel and a ditch strengthening device; the included angle between ditch strengthening plates is adjusted through a lead screw mechanism so as to change the ditch shape; the tractor hub rotating speed acquired by a spe