The invention relates to a reactor for quickly pyrolyzing solid organic matters. The reactor comprises a mixing heating zone, a pyrolytic reaction zone and gas-phase product second-order reaction zones. The pyrolytic reaction zone is arranged at the lower end of the mixing heating zone, and the gas-phase product second-order reaction zones are positioned at the side ends of the pyrolytic reactionzone; the pyrolytic reaction zone is separated from the gas-phase product second-order reaction zones by first grids; material inlets and a first auxiliary material inlet are formed in the top of themixing heating zone; a return valve is arranged on the lower portion of the pyrolytic reaction zone; second auxiliary material inlets are formed in the tops of the gas-phase product second-order reaction zones, adjusting valves are arranged on the lower portions of the gas-phase product second-order reaction zones, and gas-phase product outlets are formed in the sides of the gas-phase product second-order reaction zones; the gas-phase product second-order reaction zones are separated from the gas-phase product outlets by second grids. The reactor has the advantages that the solid organic matters can be pyrolyzed, upgraded and purified in the same reactor, the yield of liquid products can be effectively increased, and the dust contents of the liquid products can be reduced.