Abstract: This article investigated the parametric calibration of computed tomography(CT)systems and the imaging of unknown samples.Based on the received information of the calibration template,a number of optimization models were established,and the rotation angle,distance between detectors,and rotation center of the template were solved.The parameter calibration of the CT system was solved.The Fourier transform and filtered back projection method were used to establish the calibration parameters.The medium absorption rate reconstruction model was based on the value of the X-ray receiving information of the CT system,combined with the calibrated parameters,and solved by MATLAB programming.The absorption rate,shape and position of the unknown medium were obtained,and the parameter calibration and imaging of the CT system were solved.