A tomography imaging apparatus and a tomography imaging method are provided. The tomography imaging apparatus includes a data acquirer configured to acquire first X-ray data of an object for each of energy bands, and an image preprocessor configured to perform a beam hardening correction on the first X-ray data for each of the energy bands, to generate second X-ray data of the object. The tomography imaging apparatus further includes an image reconstructor configured to reconstruct a tomography image of the object based on the second X-ray data.