The QR code door opening program is a convenient electronic access control system that allows users to easily unlock the door through their mobile phones. The widespread use of this small program stems from its unique features and benefits, the most notable of which are portability and ease of use. Users can easily use it on their mobile phones. Whether it is a family, a hotel or a public place, as long as there is a need for access control, it can provide a convenient solution. The two-dimensional code generated by the program has uniqueness and timeliness, which is convenient for users to switch the access control at any time.