The present disclosure relates to a data processing method and device. The data processing method comprises steps of: performing detector response calibration based on a detector response obtained by an incidence of rays with known energy into a detector to obtain a detector response model; obtaining a photon counting model of the detector between incident energy spectrum data of the detector and detected energy spectrum data of the detector based on the detector response model; and performing a deconvolution operation on counts of photons in respective energy regions in the detected energy spectrum data of the detector based on the photon counting model of the detector, to obtain real counts of photons in respective energy regions in the incident energy spectrum data of the detector.