The invention relates to the technical field of sowing equipment, and particularly relates to a seed discharging device. The seed discharging device comprises a seed discharging device body and a rotatable outer groove wheel which is arranged on the seed discharging device body, a plurality of storage grooves are averagely distributed in the circumferential direction of the outer groove wheel, theseed discharging device body is provided with a fertilizer port, a seed inlet and a discharging port, fertilizers can enter the storage grooves from the fertilizer port, seeds can enter the storage grooves from the seed inlet, and the seeds and the fertilizers in the storage grooves can be discharged from the discharging port. The fertilizers can enter the storage grooves from the fertilizer port, and the seeds can enter the storage grooves from the seed inlet. The seeds and the fertilizers can be gathered and mixed in the storage grooves and can be discharged together from the discharging port.