Password access control can be said to be the most common and simplest access control device, and the oldest access control device. It mainly relies on the security control mode of equipment such as safes, and uses the input password to judge the identity of the incoming person. After the user enters the password, the information entered by the system in the future is identified and matched with the database. If it is correct, the electric lock is driven and the door is released. For this type of access control system, its advantages are low cost and ease of use. Users only need to remember the password to complete the “interaction” with the access control. There is no need to match any extra components to avoid the complexity and extra cost of use. However, the safety and efficiency of such access control is also the lowest. Other people can obtain the control password of the gate through observation or other simple channels, and because there are many people who know the password, there are still features that are easy to open but inconvenient to replace. Therefore, the application field of password access control is now less and less, but it is still used in places where some people use it is not very frequent, or where security requirements are not very high.