The invention discloses a combined low-rank coal rapid pyrolysis device which comprises vertical pyrolysis chambers and heating chambers which are alternately and orderly arranged side by side, wherein the heating chambers are divided into a plurality of horizontal flues; a row of stirrers are arranged in each vertical pyrolysis chamber; heating gases in one heating chamber and one vertical pyrolysis chamber which are adjacent to each other flow reversely; stirring tubes are arranged in the middle parts of the stirrers; two ends of each stirring tube are provided with an axis drum and a beam barrel respectively; the beam barrels on one side are provided with gears to drive the stirrers to rotate; in the same vertical pyrolysis chamber, the rotation direction of one stirrer is opposite to the rotation direction of the stirrers which are adjacent to the stirrer up and down; and feeding equipment is mounted at the top of each vertical pyrolysis chamber, and discharge equipment is mountedat the bottom of each vertical pyrolysis chamber. The invention adopts internal and external heating as well as dynamic and static combination, has large heating area and uniform heating, is suitablefor large-scale industrial production, avoids the defects that a direct heating method has low oil gas yield, and oil gas is difficult to be separated from dust, poor in quality and controlled after pollution and the like, and overcomes the defects of large static heating resistance, nonuniform heating, long pyrolysis time, small heating area and the like in an indirect heating method.