The utility model provides a complete-stalk investment-type combined harvester which has a low price and a simple structure, and can drive a harvesting part (10) to rotate positively and reversely. A transmission box (36) is arranged on the front side of the walking body of a threshing device (5) of the combined harvester; the transmission box is equipped with a transmission box input shaft (37) to which a driving force of an engine (10) is transmitted, the transmission box input shaft (37) is linked to threshing cylinder output shafts (38) through bevel gear mechanisms (43), wherein the threshing cylinder output shafts (38) are in the forward direction and the backward direction of the walking body on the transmission box input shaft, so that the driving force of the transmission box input shaft is transmitted to a threshing cylinder (5a), and a harvesting output shaft (39) which is linked to the transmission box input shaft through the bevel gear mechanisms so as to be driven along the rotating direction opposite to the rotating direction of the transmission box input shaft. In order to transmit the driving force in the positive rotating direction to a harvesting input shaft (42) of the harvesting part, a positive rotating clutch (40) is arranged; and in order to transmit the driving force in the reverse rotating direction to the harvesting input shaft, a reverse rotating clutch (41) is arranged.