The invention discloses a video content encryption and decryption system, which is characterized by comprising a content server, an authorization server and a client. The content server comprises a plaintext content library, a cipher text content library, a packaging encryption module and a content management module, wherein the plaintext content library is used for storing unencrypted videos; the cipher text content library is used for storing encrypted videos; the packaging encryption module encrypts digital video contents by using content keys according to a formulated encryption strategy, and packages the encrypted digital video contents and video content related information. The authorization server comprises a key database for storing all the content keys for encrypting the digital video contents, an authorization management module, an authentication management module, a key encryption module and a key generation module. The client comprises a copyright management module and an unpacking decryption playing module, wherein the copyright management module is for recording correspondence between private keys and cipher texts and verifying the integrity of a file by using a digital signature. The encryption and decryption system can effectively protect the security and integrity of data.