A CT beam hardening correction method, comprising: scanning a plurality of phantoms of different sizes by using a beam emitted by a ray source of a CT device, to obtain measured projection data of the plurality of phantoms; calculating estimated theoretical projection data of each phantom based on an initial estimated position of the phantom relative to the ray source by using a theoretical projection data calculation model; calculating an actual position of each phantom relative to the ray source based on the measured projection data of the phantom and the estimated theoretical projection data of the phantom; calculating actual theoretical projection data of each phantom by using the theoretical projection data calculation model according to the actual position of the phantom relative to the ray source; obtaining a beam hardening correction calculation model, wherein the beam hardening correction calculation model represents a relationship among expected projection data of a scanned object, measured projection data of the scanned object, and a beam hardening correction factor; using the actual theoretical projection data of each phantom as the expected projection data of the scanned object, using the measured projection data of each phantom as the measured projection data of the scanned object, and calculating the beam hardening correction factor according to the relationship by using the beam hardening correction calculation model; and using measured projection data of a measured object as the measured projection data of the scanned object and corrected projection data of the measured object as the expected projection data of the scanned object based on the calculated beam hardening correction factor, and calculating the corrected projection data of the measured object according to the relationship. scanning a plurality of phantoms of different sizes by using a beam emitted by a ray source of a CT device, to obtain measured projection data of the plurality of phantoms; calculating estimated theoretical projection data of each phantom based on an initial estimated position of the phantom relative to the ray source by using a theoretical projection data calculation model; calculating an actual position of each phantom relative to the ray source based on the measured projection data of the phantom and the estimated theoretical projection data of the phantom; calculating actual theoretical projection data of each phantom by using the theoretical projection data calculation model according to the actual position of the phantom relative to the ray source; obtaining a beam hardening correction calculation model, wherein the beam hardening correction calculation model represents a relationship among expected projection data of a scanned object, measured projection data of the scanned object, and a beam hardening correction factor; using the actual theoretical projection data of each phantom as the expected projection data of the scanned object, using the measured projection data of each phantom as the measured projection data of the scanned object, and calculating the beam hardening correction factor according to the relationship by using the beam hardening correction calculation model; and using measured projection data of a measured object as the measured projection data of the scanned object and corrected projection data of the measured object as the expected projection data of the scanned object based on the calculated beam hardening correction factor, and calculating the corrected projection data of the measured object according to the relationship.