The composition and working process of rotating cone biomass pyrolysis system were introduced. In this system, the primary reactor was three-cone-tooth type rotating cone reactor. The continuous curving fired heating stove and pneumatic transmission of heat conveyors were designed. When the reactor temperature was 550℃ and 5 kg different dryness biomass materiel was taken, the average time of production was one minuite and thirty-eight second. The bio-oil production ratio was 75.30%. The development and test of pyrolysis system provide reference basis for large biomass pyrolysis system.