An SeNB key update method, comprising: establishing, by a master Enb, MeNB, a Radio Resource Control, RRC, connection to user equipment UE, and determining a first secondary eNB SeNB and a second SeNB that are connected to the UE; calculating, by the MeNB, a key S-KeNB1 of the first SeNB and a key S-KeNB2 of the second SeNB, and sending an SeNB addition request to the first SeNB and the second SeNB, wherein the addition request to the first SeNB carries the S-KeNB1 and the addition request to the second SeNB carries the S-KeNB2; receiving, by the MeNB, a first request acknowledgment message corresponding to the SeNB addition request that is fed back by the first SeNB, and receiving a second request acknowledgment message corresponding to the SeNB addition request that is fed back by the second SeNB; and sending, by the MeNB, an RRC reconfiguration request to the UE according to the first request acknowledgment message and the second request acknowledgment message, wherein the RRC reconfiguration request carries key update information of the first SeNB and key update information of the second SeNB, so as to trigger the UE to perform key update; wherein the sending, by the MeNB, an RRC reconfiguration request to the UE according to the first request acknowledgment message and the second request acknowledgment message comprises: obtaining, by the MeNB, the key update information of the first SeNB from the first request acknowledgment message, and obtaining the key update information of the second SeNB from the second request acknowledgment message; and adding, by the MeNB, the key update information of the first SeNB and the key update information of the second SeNB to the RRC reconfiguration request, and sending the RRC reconfiguration request to the UE, wherein the RRC reconfiguration request is used to trigger the UE to calculate the S-KeNB1 and a data stream encryption decryption key Kupenc1 corresponding to the first SeNB, and the S-KeNB2 and a data stream encryption decryption key Kupenc2 corresponding to the second SeNB, so as to activate an encryption and decryption procedure. establishing, by a master Enb, MeNB, a Radio Resource Control, RRC, connection to user equipment UE, and determining a first secondary eNB SeNB and a second SeNB that are connected to the UE; calculating, by the MeNB, a key S-KeNB1 of the first SeNB and a key S-KeNB2 of the second SeNB, and sending an SeNB addition request to the first SeNB and the second SeNB, wherein the addition request to the first SeNB carries the S-KeNB1 and the addition request to the second SeNB carries the S-KeNB2; receiving, by the MeNB, a first request acknowledgment message corresponding to the SeNB addition request that is fed back by the first SeNB, and receiving a second request acknowledgment message corresponding to the SeNB addition request that is fed back by the second SeNB; and sending, by the MeNB, an RRC reconfiguration request to the UE according to the first request acknowledgment message and the second request acknowledgment message, wherein the RRC reconfiguration request carries key update information of the first SeNB and key update information of the second SeNB, so as to trigger the UE to perform key update; wherein the sending, by the MeNB, an RRC reconfiguration request to the UE according to the first request acknowledgment message and the second request acknowledgment message comprises: obtaining, by the MeNB, the key update information of the first SeNB from the first request acknowledgment message, and obtaining the key update information of the second SeNB from the second request acknowledgment message; and adding, by the MeNB, the key update information of the first SeNB and the key update information of the second SeNB to the RRC reconfiguration request, and sending the RRC reconfiguration request to the UE, wherein the RRC reconfiguration request is used to trigger the UE to calculate the S-KeNB1 and a data stream encryption decryption key Kupenc1 corresponding to the first SeNB, and the S-KeNB2 and a data stream encryption decryption key Kupenc2 corresponding to the second SeNB, so as to activate an encryption and decryption procedure. obtaining, by the MeNB, the key update information of the first SeNB from the first request acknowledgment message, and obtaining the key update information of the second SeNB from the second request acknowledgment message; and adding, by the MeNB, the key update information of the first SeNB and the key update information of the second SeNB to the RRC reconfiguration request, and sending the RRC reconfiguration request to the UE, wherein the RRC reconfiguration request is used to trigger the UE to calculate the S-KeNB1 and a data stream encryption decryption key Kupenc1 corresponding to the first SeNB, and the S-KeNB2 and a data stream encryption decryption key Kupenc2 corresponding to the second SeNB, so as to activate an encryption and decryption procedure.