Bar code encoding method for managing full life cycle of classified information

The invention provides a bar code encoding method for managing a full life cycle of classified information. A 23-bit CODE 39 code is defined, and the 23 bits sequentially comprise two bits of identifiers, one bit of version number, one bit of security level, three bits of position codes, 14 bits of timestamps and two bits of copy codes in sequence from front to back. By adopting the bar code encoding method provided by the invention, the security level of the information, the printing position, the printing time and the serial number and the copy code of each page are distinguished, unique identification of the classified information is realized, and serving as the management reference of the classified information, the bar code encoding method can be used for registering different classified identifiers for each page and the copy thereof of the information and effectively solving the unique identification and management problems of classified unit information under the coexistence of stand-alone and network environments.