Internet of Things equipment authentication and key negotiation method

The invention relates to the technical field of communication, in particular to an Internet of Things equipment authentication and key negotiation method. The method is used for identity authentication and key exchange between a visitor terminal and a central server. A preset central server contains pre-filled encrypted visitor registration information and an access time period, the registration information comprises equipment information of a visitor terminal and identity information of a visitor, and a shared root key exists between the visitor terminal and the central server; an authentication token is calculated by introducing random numbers generated by two communication parties, the random numbers used for generating the authentication token are subjected to encryption protection in a transmission process, and registration information of a visitor is dynamically encrypted, so that keys used in each communication process are different, and the risk of leakage of the keys in a channel transmission process