DNA nanostructures with programmable nanoscale patterns has been achieved in the past decades, and molecular information coding (MIC) on those designed nanostructures has gained increasing attention for information security. However, achieving steganography and cryptography synchronously on DNA nanostructures remains a challenge. Herein, we demonstrated MIC in a reconfigurable DNA origami domino array (DODA), which can reconfigure intrinsic patterns but keep the DODA outline the same for steganography. When a set of keys (DNA strands) are added, the cryptographic data can be translated into visible patterns within DODA. More complex cryptography with the ASCII code within a programmable 6×6 lattice is demonstrated to demosntrate the versatility of MIC in the DODA. Furthermore, an anti‐counterfeiting approach based on conformational transformation‐mediated toehold strand displacement reaction is designed to protect MIC from decoding and falsification. The DNA Code: A novel steganography and cryptography molecular information coding (MIC) strategy in a reconfigurable DNA origami domino array (DODA) is demonstrated. This strategy opens new opportunities for high‐density information storage and information security against decoding, duplication, and forgery, overcoming the key difficulties in MIC technologies.