A path switching method, comprising: receiving, by a mobility anchor, a path switch request message sent by a target base station; keeping, by the mobility anchor, a user plane path between the mobility anchor and a serving gateway SGW unchanged if the mobility anchor is to switch a local path; and switching, by the mobility anchor, a user plane path between the mobility anchor and a source base station to the target base station; wherein the method is characterised in that the method further comprises: generating, by the mobility anchor, a first next-hop NH parameter; and sending, by the mobility anchor, the first NH parameter to the target base station by using a path switch request acknowledgment message, so that the target base station determines, according to the first NH parameter, a key used by a next base station, wherein the next base station is a base station other than the source base station and the target base station; wherein the generating, by the mobility anchor, a first NH parameter comprises: generating, by the mobility anchor, the first NH parameter according to a second source base station key and a random number; wherein the method further comprises: receiving, by the mobility anchor, the second source base station key sent by the MME, wherein the second source base station key is determined by the MME according to an access security management entity key and a non-access stratum counter; or the second source base station key is determined by the MME according to the access security management entity key and an identifier of the mobility anchor. receiving, by a mobility anchor, a path switch request message sent by a target base station; keeping, by the mobility anchor, a user plane path between the mobility anchor and a serving gateway SGW unchanged if the mobility anchor is to switch a local path; and switching, by the mobility anchor, a user plane path between the mobility anchor and a source base station to the target base station; wherein the method is characterised in that the method further comprises: generating, by the mobility anchor, a first next-hop NH parameter; and sending, by the mobility anchor, the first NH parameter to the target base station by using a path switch request acknowledgment message, so that the target base station determines, according to the first NH parameter, a key used by a next base station, wherein the next base station is a base station other than the source base station and the target base station; generating, by the mobility anchor, a first next-hop NH parameter; and sending, by the mobility anchor, the first NH parameter to the target base station by using a path switch request acknowledgment message, so that the target base station determines, according to the first NH parameter, a key used by a next base station, wherein the next base station is a base station other than the source base station and the target base station; wherein the generating, by the mobility anchor, a first NH parameter comprises: generating, by the mobility anchor, the first NH parameter according to a second source base station key and a random number; wherein the method further comprises: receiving, by the mobility anchor, the second source base station key sent by the MME, wherein the second source base station key is determined by the MME according to an access security management entity key and a non-access stratum counter; or the second source base station key is determined by the MME according to the access security management entity key and an identifier of the mobility anchor. generating, by the mobility anchor, the first NH parameter according to a second source base station key and a random number; wherein the method further comprises: receiving, by the mobility anchor, the second source base station key sent by the MME, wherein the second source base station key is determined by the MME according to an access security management entity key and a non-access stratum counter; or the second source base station key is determined by the MME according to the access security management entity key and an identifier of the mobility anchor.