A method and device for X-ray scanning based on dose, comprising: receiving an X-ray dose for scanning set for a region of a subject to be scanned, selecting a scanning and reconstructing technology combination according to said pre-set X-ray dose for scanning wherein the demanded X-ray dose of the selected scanning and reconstructing technology combination satisfies said pre-set X-ray dose for scanning, and scanning said region and implementing a reconstruction accordingly with the selected scanning and reconstructing technology combination to obtain a resultant scanning image.
