Disclosed are a data encryption method, server and system based on a delivered encryption algorithm. The system comprises: a server, used for randomly generating an encryption algorithm according to request information of a client, converting the encryption algorithm into a rule character text of a client executable code, and delivering the rule character text to the client according to a preset delivery rule; a client, used for receiving encrypted data delivered by the server according to the preset delivery rule, restoring the encrypted data into the client executable code according to a preset decryption rule matching the delivery rule, and encapsulating uploaded data according to the code. The data encryption method, server and system based on a delivered encryption algorithm of the present invention improve data transmission security and maintenance convenience while reducing maintenance costs.
