A route optimization method, wherein the method comprises: establishing a forwarding tunnel between a first mobile router, MR, in a network in which a first user equipment, UE, is currently located and a second MR, in a network in which a second UE is currently located, wherein at least one UE of the first UE and the second UE is currently located in a visited network; and transmitting data between the first UE and the second UE over the forwarding tunnel; wherein the establishing a forwarding tunnel between a first MR in a network in which first UE is currently located and a second MR, in a network in which second UE is currently located comprises: sending, by the first MR, a first route request message to a home location manager, H-LM, entity of the second UE, wherein the first route request message comprises an Internet Protocol IP address of the second UE acquired by the first MR from a packet sent by the first UE with the destination of the second UE, and wherein the H-LM is determined as the location manager corresponding to the IP address of the second UE; receiving, by the first MR, a first route response message sent by the H-LM of the second UE, wherein the first route response message comprises an address of the second MR; and establishing, by the first MR, a forwarding tunnel between the first MR and the second MR according to the address of the second MR. establishing a forwarding tunnel between a first mobile router, MR, in a network in which a first user equipment, UE, is currently located and a second MR, in a network in which a second UE is currently located, wherein at least one UE of the first UE and the second UE is currently located in a visited network; and transmitting data between the first UE and the second UE over the forwarding tunnel; wherein the establishing a forwarding tunnel between a first MR in a network in which first UE is currently located and a second MR, in a network in which second UE is currently located comprises: sending, by the first MR, a first route request message to a home location manager, H-LM, entity of the second UE, wherein the first route request message comprises an Internet Protocol IP address of the second UE acquired by the first MR from a packet sent by the first UE with the destination of the second UE, and wherein the H-LM is determined as the location manager corresponding to the IP address of the second UE; receiving, by the first MR, a first route response message sent by the H-LM of the second UE, wherein the first route response message comprises an address of the second MR; and establishing, by the first MR, a forwarding tunnel between the first MR and the second MR according to the address of the second MR. sending, by the first MR, a first route request message to a home location manager, H-LM, entity of the second UE, wherein the first route request message comprises an Internet Protocol IP address of the second UE acquired by the first MR from a packet sent by the first UE with the destination of the second UE, and wherein the H-LM is determined as the location manager corresponding to the IP address of the second UE; receiving, by the first MR, a first route response message sent by the H-LM of the second UE, wherein the first route response message comprises an address of the second MR; and establishing, by the first MR, a forwarding tunnel between the first MR and the second MR according to the address of the second MR.