The utility model relates to a crawler chassis of a sectional type green Chinese onion harvester. Wherein the guide wheel, the thrust wheel and the branch guide wheel are installed on the frame. The caterpillar band is wound on the guide wheel, the thrust wheel and the branch guide wheel; wherein an engine, a hydraulic oil pump and a gearbox are fixedly arranged on the frame, the hydraulic oil pump and the gearbox are driven by the engine, an output shaft of the gearbox is fixedly connected with a driving wheel located above the frame, the driving wheel is located in a crawler belt and meshedwith the crawler belt, and a crawler belt tensioning device installed on the frame is arranged in the crawler belt. The crawler belt is driven to rotate by the driving wheel positioned above the frame, so that the walking stability of the equipment is improved, the force transmission loss is small, the traction force is increased, and the driving requirements of different soils are met.