The invention discloses a technology and a device for removing particles from a biomass pyrolysis liquid fluidized bed reactor. The technology comprises the following steps: A) performing cyclone classification to separate catalyst micro-powder having a particle size of below 0.1 mm; B) performing filtering separation to separate out the micro-powder from conveyed oil/alcohol; C) performing cyclone rotation drying to remove oil/alcohol carried by the micro-powder to achieve drying and quantity reduction; and D) purifying a gas to remove the oil/alcohol carried in the gas in order to achieve carrier gas circulation. The device is mainly composed of a biomass pyrolysis liquid fluidized bed reactor, a cyclone classifier, a filter, a cyclone rotator, a gas purification tower and a pipeline heater. The technology and the device can meet the requirements for achieving the classification of the particles and realizing the drying and quantity reduction of the separated catalyst.