A method for controlling signalling transmission in a power-saving mode, comprising: a) transmitting, by a terminal, a tracking area update, TAU, request signalling or a routing area update, RAU, request signalling to a new mobility management unit, wherein the TAU request signalling and the RAU request signalling each comprises a power-saving parameter; and b) transmitting, by the new mobility management unit, the power-saving parameter to an old mobility management unit, wherein step b) further comprises: b1) transmitting (202, 302), by the new mobility management unit, a context request signalling to the old mobility management unit; b2) transmitting (203, 303), by the old mobility management unit, a context response signalling to the new mobility management unit, wherein the context response signalling comprises an Idle mode Signalling Reduction, ISR, mode supported indication; and b3) transmitting (204, 304), by the new mobility management unit, a context confirmation signalling to the old mobility management unit, wherein the context confirmation signalling comprises an ISR activation indication and the power-saving parameter, the ISR activation indication representing whether an ISR mode has been activated, characterized in that step b) further comprises: b4) when a serving gateway transmits a notification signalling to the new mobility management unit and the old mobility management unit in response to a case that there is data needed to be transmitted to the terminal (207,307), determining, by the new mobility management unit and the old mobility management unit according to the power-saving parameter of the terminal, that: the new mobility management unit and the old mobility management unit transmit a paging message to the terminal if current time is within activation time of the terminal (209, 309); and the new mobility management unit and the old mobility management unit transmit a feedback signalling to the serving gateway if current time is within non-activation time of the terminal, wherein the feedback signalling comprises a delay indication. a) transmitting, by a terminal, a tracking area update, TAU, request signalling or a routing area update, RAU, request signalling to a new mobility management unit, wherein the TAU request signalling and the RAU request signalling each comprises a power-saving parameter; and b) transmitting, by the new mobility management unit, the power-saving parameter to an old mobility management unit, wherein step b) further comprises: b1) transmitting (202, 302), by the new mobility management unit, a context request signalling to the old mobility management unit; b2) transmitting (203, 303), by the old mobility management unit, a context response signalling to the new mobility management unit, wherein the context response signalling comprises an Idle mode Signalling Reduction, ISR, mode supported indication; and b3) transmitting (204, 304), by the new mobility management unit, a context confirmation signalling to the old mobility management unit, wherein the context confirmation signalling comprises an ISR activation indication and the power-saving parameter, the ISR activation indication representing whether an ISR mode has been activated, characterized in that step b) further comprises: b4) when a serving gateway transmits a notification signalling to the new mobility management unit and the old mobility management unit in response to a case that there is data needed to be transmitted to the terminal (207,307), determining, by the new mobility management unit and the old mobility management unit according to the power-saving parameter of the terminal, that: the new mobility management unit and the old mobility management unit transmit a paging message to the terminal if current time is within activation time of the terminal (209, 309); and the new mobility management unit and the old mobility management unit transmit a feedback signalling to the serving gateway if current time is within non-activation time of the terminal, wherein the feedback signalling comprises a delay indication. b1) transmitting (202, 302), by the new mobility management unit, a context request signalling to the old mobility management unit; b2) transmitting (203, 303), by the old mobility management unit, a context response signalling to the new mobility management unit, wherein the context response signalling comprises an Idle mode Signalling Reduction, ISR, mode supported indication; and b3) transmitting (204, 304), by the new mobility management unit, a context confirmation signalling to the old mobility management unit, wherein the context confirmation signalling comprises an ISR activation indication and the power-saving parameter, the ISR activation indication representing whether an ISR mode has been activated, the new mobility management unit and the old mobility management unit transmit a paging message to the terminal if current time is within activation time of the terminal (209, 309); and the new mobility management unit and the old mobility management unit transmit a feedback signalling to the serving gateway if current time is within non-activation time of the terminal, wherein the feedback signalling comprises a delay indication.