An imaging method, applied in a photon-counting CT system, said photon-counting CT system comprising an X-ray source, said X-ray source being a tube, a shape filter, and a photon-counting detector, the imaging method comprising: scanning a subject to obtain a photon-counting sequence outputted by said photon-counting detector of the photon-counting CT system, said photon-counting detector comprising multiple sub-detectors; determining, by using a photon-counting model and the photon-counting sequence, a target material distribution parameter value of the subject, the photon-counting model being created by at least one of a charge sharing model, an energy resolution model, or a pulse pileup model, the charge sharing model being configured to eliminate energy spectrum distortion and counting loss caused by charge sharing, the energy resolution model being configured to eliminate energy spectrum distortion and counting loss caused by energy resolution, and the pulse pileup model being configured to eliminate energy spectrum distortion and counting loss caused by pulse pileup; performing imaging based on the target material distribution parameter value; characterized in that, the method further comprises: determining a tube emission energy spectrum corresponding to an exposure voltage, an exposure current, and an exposure time; and for each of sub-detectors of the photon-counting detector under each scanning view, determining an attenuation length of rays passing through said shape filter of the photon-counting CT system as a first attenuation length, wherein the rays enter into the sub-detector after passing through the subject under the scanning view; for each voxel of the subject, determining an attenuation length of the rays passing through the voxel as a second attenuation length; and determining an incident ray energy spectrum of the sub-detector under the scanning view based on the tube emission energy spectrum, the first attenuation length, and the second attenuation length and a material distribution parameter value of each said voxel of the subject. scanning a subject to obtain a photon-counting sequence outputted by said photon-counting detector of the photon-counting CT system, said photon-counting detector comprising multiple sub-detectors; determining, by using a photon-counting model and the photon-counting sequence, a target material distribution parameter value of the subject, the photon-counting model being created by at least one of a charge sharing model, an energy resolution model, or a pulse pileup model, the charge sharing model being configured to eliminate energy spectrum distortion and counting loss caused by charge sharing, the energy resolution model being configured to eliminate energy spectrum distortion and counting loss caused by energy resolution, and the pulse pileup model being configured to eliminate energy spectrum distortion and counting loss caused by pulse pileup; performing imaging based on the target material distribution parameter value; characterized in that, the method further comprises: determining a tube emission energy spectrum corresponding to an exposure voltage, an exposure current, and an exposure time; and for each of sub-detectors of the photon-counting detector under each scanning view, determining an attenuation length of rays passing through said shape filter of the photon-counting CT system as a first attenuation length, wherein the rays enter into the sub-detector after passing through the subject under the scanning view; for each voxel of the subject, determining an attenuation length of the rays passing through the voxel as a second attenuation length; and determining an incident ray energy spectrum of the sub-detector under the scanning view based on the tube emission energy spectrum, the first attenuation length, and the second attenuation length and a material distribution parameter value of each said voxel of the subject. determining a tube emission energy spectrum corresponding to an exposure voltage, an exposure current, and an exposure time; and for each of sub-detectors of the photon-counting detector under each scanning view, determining an attenuation length of rays passing through said shape filter of the photon-counting CT system as a first attenuation length, wherein the rays enter into the sub-detector after passing through the subject under the scanning view; for each voxel of the subject, determining an attenuation length of the rays passing through the voxel as a second attenuation length; and determining an incident ray energy spectrum of the sub-detector under the scanning view based on the tube emission energy spectrum, the first attenuation length, and the second attenuation length and a material distribution parameter value of each said voxel of the subject. determining an attenuation length of rays passing through said shape filter of the photon-counting CT system as a first attenuation length, wherein the rays enter into the sub-detector after passing through the subject under the scanning view; for each voxel of the subject, determining an attenuation length of the rays passing through the voxel as a second attenuation length; and determining an incident ray energy spectrum of the sub-detector under the scanning view based on the tube emission energy spectrum, the first attenuation length, and the second attenuation length and a material distribution parameter value of each said voxel of the subject.