The invention relates to a digital camera calibration method targeted to shield tunnel hazard digital radiography detection, which particularly includes the following steps: preparing a standard calibration line as well as a calibration board for a computer vision kit Halcon; setting positions of photograph sites by taking longest and shortest photographing distances possibly occurring on the actual shield tunnel site into consideration; fixing a camera on a tripod to photograph the photograph sites sequentially so as to obtain calibration images; processing calibration board images on all photograph sites by utilizing a Haocon calibration procedure, so as to obtain camera intrinsic parameters on the sites; performing the lens radial distortion correction for standard calibration line images obtained on the sites by utilizing the camera intrinsic parameters on the photograph sites; through an identification and measurement procedure, obtaining the pixel widths of three calibration lines as per the distortion corrected images, and obtaining the mean value, wherein the specific value of the actual width of the standard calibration line to the mean value is R, the photographing distance is D, and the calibration function R (D) is obtained after curve fitting. The method has the advantages of low calculation quantity, stable result, convenience, rapidness and the like.