Device and method for continuously preparing high-purity AKD without solvent includes a reactor making continuous mixing of raw materials. The process includes: the tertiary amine feeding into the reactor and the continuously feeding acyl chloride from three to ten line; under operating state, the motor rotates the internal cylinder in relation to external cylinder, forcing the fed materials to convey and stir in the conveying section of annular column passage, forcing the materials to shear and mix by movement of shearing and kneading blades. Arrangement of conveying and mixing sections along the axial direction of annular column passage, causes sufficient reaction of materials and controls the material temperature through internal and external heat exchange systems until the reaction products are discharged from outlet. The device and process disperse reaction heat and sufficient material mixture and complete reaction to control the reaction temperature, viscosity and decrease the generation of side reaction.