The invention discloses a device for reaction phase change type capturing of CO2. The device comprises a mixing type stirring assembly. The mixing type stirring assembly comprises a tank body, a suspension outlet pipe, a valve, a solid absorbent inlet pipe, an absorbent rich liquid inlet pipe, a motor, a rotating shaft, stirring blades, a connecting rod and scraping plates, wherein one side of thetank body communicates with one end of the absorbent rich liquid inlet pipe, and the absorbent rich liquid inlet pipe communicates with the water outlet end of a second water pump. Directed at the solid-liquid phase change characteristics of a reaction phase change type absorbent in the process of absorbing CO2, the device provided by the invention has an additional mixing type stirring tank compared with conventional processes; and a prepared suspension retains the solid state characteristics of the reaction phase change type absorbent before absorption and also significantly increases the CO2 capturing rate of the absorbent. The device utilizes the latent heat of the reaction phase change type absorbent during regeneration, and can provide partial heat to a desorption tower, thereby effectively reducing regeneration energy consumption during the capturing process of CO2.