The invention discloses a two-dimensional code image optical encryption method and system, a device and a storage medium. An original image to be encrypted is stored by using a two-dimensional code image; carrying out gray scale transformation on the two-dimensional code image; obtaining a transformed two-dimensional code pixel matrix; then, carrying out optical encryption operation based on fractional Fourier transform on the image; and after the encryption operation, carrying out threshold-based effective information extraction and integration operation to obtain a final encrypted image, sothat introduction of extra system complexity can be avoided, noise crosstalk among a plurality of images is reduced, and lossless recovery of the original image in a later decryption process is facilitated by using the two-dimensional code as a container of the original image.