The invention provides an information encryption method based on a DNA nanotechnology. The method comprises the steps that origami is used to form a structure with a design pattern as a plain text, wherein the structure has the designed pattern; a key single chain is added, and the designed pattern disappears, so as to hide information to form a square origami without mark information; when writing is carried out, the position of the mark information is encrypted; and the result of encrypted storage can be visually observed through AFM. The invention further comprises a corresponding information recovery method. The key single chain is added to recover the plain text to realize information recovery and decryption. According to the invention, the DNA origami and a chain replacement technology are combined; a DNA chain is used as a carrier for information storage; encrypted storage and recovery of molecular level information are realized through formation and decomposing of the pattern on the square origami; and the method is feasible and effective for information encryption storage and recovery, and provides an experimental basis for promoting the development of a nano-scale biological information storage technology.