Data encryption technology is the most basic security technology, known as the core of information security, mainly used to ensure the security of data in the process of storage and transmission. It is to convert the plaintext file or data into unreadable code according to some algorithm, usually called "ciphertext", and then only input the corresponding key to display the content of the original plaintext, on the contrary, the process of converting the encoded information into the original data information is called decryption, through this encryption method to protect the data. Taking the intelligent water meter as an example, this paper introduces the application of data encryption technology in the intelligent IC card meter. 

In order to solve the data security of IC card, it is necessary to back up the corresponding data information in a comprehensive, reliable, safe and multi-level way first The data is encrypted. Data encryption technology can be divided into three parts: data encryption, secure transmission and identity authentication. 

In the process of storage or transmission, even if the encrypted information is obtained by unauthorized personnel, it can be ensured that the information is not recognized, so as to achieve the purpose of protecting data information. The security of this method depends directly on the algorithm and key length. Data encryption technology is recognized as the only practical method to protect data transmission and data storage.