The utility model relates to a mechanical precision seed-metering device, which belongs to a mechanical seed-metering device. The mechanical precision seed-metering device solves the problems existing in the former mechanical seed-metering device that the precision seeding cannot be carried out, and the manpower and the material resources are wasted; the mechanical precision seed-metering device comprises a seed chamber and a sowing axle connected with a planter plate after penetrating the seed chamber, wherein the planter plate is closely stuck on the inner wall of the seed chamber, evenly distributed through-holes are manufactured on the edge of the planter plate, scoop bodies are manufactured near the through-holes, a seed discharging pipe is manufactured on the outer side of the seed chamber, and the position of the seed discharging pipe is corresponding to the position of a seed discharging hole on the side wall of the seed chamber. The utility model can perform precision seeding, realize single grain sowing, reduce the breaking ratio of the seeds, and save the seeds, the farming season and the labor force.