The invention aims to provide a method for removing organic and inorganic matters from security inspection images. The method restores the display effect of original images of organic matters or inorganic matters in an unobstructed state as truly as possible and is embodied in the following two aspects: (1) accurately restoring the original colors of obstructed target organic matters or inorganic matters; and (2) restoring the gray values of the obstructed target organic matters or inorganic matters into unobstructed original values and evaluating with the index of effective thickness range. Compared with the prior art, the invention has the advantages that security personnel can easily distinguish hidden suspicious objects by adopting equipment with the removing function for further treatment. The invention improves the judgment accuracy and the working efficiency of the security personnel to a great extend, greatly enhances the security inspection level and is significant to the traffic safety of aviation and the like.