The invention discloses an organic waste pyrolysis system and a method for treating organic waste through the organic waste pyrolysis system. The organic waste pyrolysis system comprises a screening machine, a spiral feeder, a drying hoist tower, a first cyclone separator and a pyrolysis reactor, wherein the screening machine, the spiral feeder, the drying hoist tower, the first cyclone separator and the pyrolysis reactor are communicated in sequence. The system can effectively restrain a secondary reaction of oil gas and increase the yield of tar, heat-storage non-heat-carrier radiant tubes are adopted for heating by the utilization of dividing wall heat exchanging, gas and solid heat carriers are not needed, the heat value of pyrolysis gas is increased, and meanwhile the organic waste pyrolysis system can be combined in a modularized mode, and is suitable for different amount of waste to be treated and easy to industrialize.