A data security processing method, comprising: setting up (S101) a first protocol data unit PDU session between a first base station and a user equipment UE, deriving, by the first base station, a first user plane key based on a received base key, and performing, by the first base station, security processing on user plane data in the first PDU session by using the first user plane key and a security algorithm; and setting up (S102) a second PDU session between the first base station and the UE, deriving, by the first base station, a second user plane key based on the base key, and performing, by the first base station, security processing on user plane data in the second PDU session by using the second user plane key and the security algorithm; wherein a user plane key comprises a user plane encryption key and/or a user plane integrity protection key, wherein the deriving, by a first base station, a first user plane key based on a received base key comprises: deriving, by the first base station, the first user plane key based on the base key and a first parameter, wherein the first parameter is a first PDU session identifier of the first PDU session; and the deriving, by the first base station, a second user plane key based on the base key comprises: deriving, by the first base station, the second user plane key based on the base key and a second parameter, wherein the second parameter is a second PDU session identifier of the second PDU session. setting up (S101) a first protocol data unit PDU session between a first base station and a user equipment UE, deriving, by the first base station, a first user plane key based on a received base key, and performing, by the first base station, security processing on user plane data in the first PDU session by using the first user plane key and a security algorithm; and setting up (S102) a second PDU session between the first base station and the UE, deriving, by the first base station, a second user plane key based on the base key, and performing, by the first base station, security processing on user plane data in the second PDU session by using the second user plane key and the security algorithm; wherein a user plane key comprises a user plane encryption key and/or a user plane integrity protection key, wherein the deriving, by a first base station, a first user plane key based on a received base key comprises: deriving, by the first base station, the first user plane key based on the base key and a first parameter, wherein the first parameter is a first PDU session identifier of the first PDU session; and the deriving, by the first base station, a second user plane key based on the base key comprises: deriving, by the first base station, the second user plane key based on the base key and a second parameter, wherein the second parameter is a second PDU session identifier of the second PDU session. deriving, by the first base station, the first user plane key based on the base key and a first parameter, wherein the first parameter is a first PDU session identifier of the first PDU session; and the deriving, by the first base station, a second user plane key based on the base key comprises: deriving, by the first base station, the second user plane key based on the base key and a second parameter, wherein the second parameter is a second PDU session identifier of the second PDU session. <EOS>