An information transmission method, comprising: sending (S201), 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 (S205), 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 (S206), 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 (S201), 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 (S205), 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 (S206), 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 . <EOS>