The utility model relates to a combined water chestnut harvester. The combined water chestnut harvester comprises a hydraulic crawling chassis, and the hydraulic crawling chassis is provided with a driver cab, a car, a diesel engine power mechanism, an excavating and conveying device, a vibrating screen, a mud pump cleaning device, a rotating cage high-pressure air pump air-drying device and a field leveling harrow. The combined water chestnut harvester can eliminate residual water chestnut straws and weeds in fields, excavate water chestnuts from soil, clean soil and water on water chestnuts and recover the excavated pitted fields to an original flat state. The combined water chestnut harvester achieves harvesting mechanization of the water chestnuts and greatly improves the harvesting quality and the harvesting efficiency of the water chestnuts.