File encryption method and system

The invention discloses a file encryption method and system, and the method comprises the steps: obtaining and processing face video dynamic and original voice information, and obtaining face feature information and voiceprint feature information; fusing the identity information into identity feature information to serve as a first encryption key; obtaining an initial file and processing according to the byte importance of the initial file to obtain a first file and a second file; converting the first file into an initial image, and encrypting the initial image through a chaos iterative encryption algorithm and pixel replacement to obtain an encrypted transmission image; fusing the first encryption key and the initial image to obtain a second encryption key, and encrypting the second file to obtain an encrypted transmission file; and encrypting the encrypted transmission image and the file through the first encryption key and transmitting the encrypted transmission image and the file to a target end. The secr