China's new generation meteorological satellites provide a variety of measurements,and various data need to be transmitted with different data transmission modes.To ensure that a certain kind of detection data can be appropriately used in specific conditions by only those who are authorized,encryption and decryption technology is applied in data transmission.Before transmission, data are encrypted with the encryption key on satellites;on the ground,the decryption keys are assigned to authorized users.The encryption and decryption algorithm of data processing for our new generation meteorological satellites is introduced,and the decryption process realized by software is described.