The invention discloses an information coding inner layer structure, and belongs to the technical field of packaging transportation, encryption and decryption and information security. The informationcoding inner layer structure is characterized in that a first disc, a second disc and a third disc are arranged on the surface of the information coding inner layer structure; the first disc comprises n step periods of which the central angles form an arithmetic progression in the circumferential direction, and the step height in each step period monotonically changes; the second disc comprises pi step periods in the circumferential direction, and the step height in each step period monotonically changes; and the third disc comprises a starting line and n position lines in the circumferentialdirection. According to the information coding inner layer structure, the mode that the personal information is directly displayed on the express bill can be changed, so that the problem that the personal information is leaked through the express bill is fundamentally solved.