The invention discloses a data transmission method and a data transmission system in an electric power communication system. According to the method, after identity authentication is carried out, and user identity is determined to be correct, an information acquisition instruction of a user is received by an information acquisition server, after the user is confirmed to have authority to acquire to-be-acquired information, the instruction is sent to a server through isolation equipment arranged between a non-control production area and a management information area, the to-be-acquired data is encrypted by the server and is fed back to the information acquisition server, through identity authentication, the isolation equipment and data encryption, data transmission safety is guaranteed, and safety and reliability of the electric power communication system are further guaranteed.