Related to are a device and a method for performing continuous carbonation and impurity removal for xylose mother liquor. The device includes an alkali addition unit, a continuous carbonating unit, a discharge controlling unit, a CO2 supply station, a vapor station and an after-carbonation tank, wherein the alkali addition unit is configured to add Ca(OH)2 alkaline liquid into xylose mother liquor, the continuous carbonating unit is configured to introduce CO2 supplied from the CO2 supply station into the alkali-added xylose mother liquor to perform carbonation and mixing so as to remove impurities such as colloid and pigment in xylose mother liquor, the discharge controlling unit is configured to introduce CO2 supplied from the CO2 supply station and vapor transported from the vapor station into the carbonated xylose mother liquor so as to control and stabilize a pH value of the carbonated xylose mother liquor, and the after-carbonation tank is configured to collect and temporarily store the carbonated and impurity-removed xylose mother liquor so as to prepare for a next procedure. Further, a method using the device is disclosed. According to the device and the method, the pH of xylose mother liquor is continuously regulated and stabilized and continuous feeding and discharge are performed with highly automated device so as to achieve continuous and uninterrupted production, and thus facilitate improving the production efficiency.