The invention relates to a data encryption method based on NFC chip security authentication. The method comprises the following steps: 1. The correct user name and password are entered by the user through the mobile terminal to verify the login; 2. After the login of the user is confirmed to be successful, a secret key in character string format is generated through the irreversible encryption of the user name, password and timestamp. To prevent the interactive data between the APP mobile terminal (NFC mobile phone) and the server (cloud server) is maliciously tampered with, cross-use of the 'reversible encryption' and the 'irreversible encryption' algorithms is adopted to ensure that interactive data between the mobile and the server terminals is absolutely safe.