This application provides a key derivation algorithm negotiation method and an apparatus. The method includes: checking, by a terminal, a sent first key derivation algorithm and a received second key derivation algorithm; if the checking is correct and the first key derivation algorithm is the same as the second key derivation algorithm, determining that the first key derivation algorithm sent by the terminal is not tampered with by an attacker; and then using a negotiated third key derivation algorithm as a key derivation algorithm of the terminal, to ensure confidentiality of the negotiated key derivation algorithm, thereby improving communication security.