Media cipher/decipher switching method and device

The invention provides a media cipher/decipher switching method and a media cipher/decipher switching device. The method comprises that first terminal equipment loads cipher/decipher programs in correspondence with all media ciphers and deciphers in a media cipher/decipher intersection, wherein, the media ciphers and deciphers contained in the media cipher/decipher intersection are supported by both the first terminal equipment and second terminal equipment; the first terminal equipment determines media ciphers and deciphers required to be switched during the session process of the second terminal equipment; the first terminal equipment employs first media ciphers contained in the media cipher/decipher intersection to code to-be-transmitted media information; and the first terminal equipment sends a media message which is obtained by coding the first media ciphers to the second terminal equipment, wherein the media message includes identification information of the first media ciphers. According to the invention, media ciphers and deciphers can be timely switched.