This application provides an RRC connection resume method and apparatus. In the method, when a terminal moves to a target base station, the target base station may reselect, based on a capability and a requirement of the target base station, a first encryption algorithm and a first integrity protection algorithm that are used when the target base station communicates with the terminal, and send the first encryption algorithm and the first integrity protection algorithm to the terminal. On one hand, a security algorithm used for communication between the terminal and the target base station is flexibly selected. On the other hand, because the base station connected to the terminal changes, communication security can be improved by using a new encryption algorithm and integrity protection algorithm.