Air-suction type precise seed-metering device with single-plate double-side seed metering function

The invention discloses an air-suction type precise seed-metering device with a single-plate double-side seed metering function. The air-suction type precise seed-metering device comprises a seed-metering shell and a seed-metering plate, wherein the seed-metering shell comprises a first seed-metering shell and a second seed-metering shell; two groups of negative pressure holes are formed in the seed-metering plate; each group of negative pressure holes comprise a plurality of negative pressure holes which are arrayed along the peripheral direction; an outer negative pressure cavity and a first seed outlet, which are matched with the negative pressure holes far away from the rotation center of the seed-metering plate, are formed in the inner side, close to the seed-metering plate, of the first seed-metering shell; a first seed inlet, which penetrates to an inner side space, is formed in the outer side of the first seed-metering shell; an inner negative pressure cavity and a second seed outlet, which are matche