An information transmission method, comprising: sending, by a first base station, a first indication to a terminal, which moves from the first base station to a second base station, wherein the first indication comprises a first identifier allocated by the first base station to the terminal, the first indication is used to instruct the terminal to enter a non-connected mode, and the first identifier is an identifier of the terminal in the non-connected mode representing a third mode of the terminal other than an idle mode and a connected mode in an area configured by the first base station; receiving, by the first base station, a request message from the second base station, wherein the request message is used to request a context of the terminal from the first base station, and the request message comprises the first identifier; and sending, by the first base station, the context of the terminal to the second base station, when the terminal in the non-connected mode moves to a cell of the second base station, wherein the first base station is a first radio access technology, RAT, base station, and the second base station is a second radio access technology, RAT, base station, wherein the sending, by the first base station, the context of the terminal to the second base station comprises: sending, by the first base station, a first radio access technology, RAT, radio resource control, RRC, context of the terminal, including an RRC configuration of the first RAT generated by the first base station, and a core network-related context of the terminal to the second base station, wherein the core network-related context is core network-related information in the context of the terminal. sending, by a first base station, a first indication to a terminal, which moves from the first base station to a second base station, wherein the first indication comprises a first identifier allocated by the first base station to the terminal, the first indication is used to instruct the terminal to enter a non-connected mode, and the first identifier is an identifier of the terminal in the non-connected mode representing a third mode of the terminal other than an idle mode and a connected mode in an area configured by the first base station; receiving, by the first base station, a request message from the second base station, wherein the request message is used to request a context of the terminal from the first base station, and the request message comprises the first identifier; and sending, by the first base station, the context of the terminal to the second base station, when the terminal in the non-connected mode moves to a cell of the second base station, wherein the first base station is a first radio access technology, RAT, base station, and the second base station is a second radio access technology, RAT, base station, wherein the sending, by the first base station, the context of the terminal to the second base station comprises: sending, by the first base station, a first radio access technology, RAT, radio resource control, RRC, context of the terminal, including an RRC configuration of the first RAT generated by the first base station, and a core network-related context of the terminal to the second base station, wherein the core network-related context is core network-related information in the context of the terminal.