Method and system for grading and sharing authority and reconstructing secret image

The invention provides a method and system for grading and sharing authority and reconstructing a secret image, and the method comprises the steps: obtaining a secret image, and setting the related parameters of the secret image according to an authority grading image secret sharing method; according to a Chinese remainder theorem method, sharing the secret image to obtain a shadow image, the shadow image including a core shadow image and a non-core shadow image; the core shadow sub-images and the non-core shadow sub-images meeting the preset number are selected to be reconstructed, and a secret image can be reconstructed; the preset number is not smaller than the second parameter, and the number of core shadow images contained in the preset number is equal to the first parameter. The core shadow image and the non-core shadow image are obtained through the authority grading secret image sharing method based on the Chinese remainder theorem, and the secret image sharing process is safer; through the core shado