Data encryption method

The invention discloses a data encryption method which comprises the following steps of generating an encryption key, and generating a group of sub-keys by the encryption key according to a predetermined rule; B. packing input plain text data randomly to generate a plurality of plain text data blocks; C. selecting a corresponding sub-key and carrying out encryption operation on the sub-key according to size of each plain text data block and the predetermined rule to obtain a plurality of encrypted data blocks; and D. forming output encrypted data by the plurality of the encrypted data blocks. The data encryption method disclosed by the invention has the advantages of being high in encryption strength, quick in operation speed, low in operation system expense, capable of being expanded and optimized, and the like, and is suitable for storage and transmission encryption of mobile equipment.