A method and system for data encryption/decryption in client-server architecture, In the invention, channel data is differentiated into a plurality of channels. The data encryption/decryption system comprises a service system and a client system. The service system is used for transmitting encrypted channels and the client system is used for receiving encrypted channels. The service system comprises an encryption unit, which encrypts a plurality of channels with various encrypting means. The client system comprises a channel-receiving unit and a plurality of decryption units; wherein the channel-receiving unit is used for selecting channels and decryption units are required to be moved onto the top of the receiving unit of respective channels to start encryption. Then displays decrypted channels on the decryption unit.