An inter-RAT measurement method, wherein the method comprises: sending, by a control node in a first RAT network, a measurement control message to a user equipment, UE, in the first RAT network, wherein each connected-discontinuous reception, C-DRX, cycle comprises a dormant period and an active period, and the measurement control message is used to instruct the UE to measure signal quality of a second RAT network in a dormant period of a first C-DRX cycle; the method further comprises: disabling, by the control node, a first inactive-period timer, wherein the first inactive-period timer is used to perform timing for the control node in an active period of the first C-DRX cycle; and performing, by the control node, downlink transmission for the UE in the active period of the first C-DRX cycle; after the sending, by a control node in a first RAT network, a measurement control message to UE in the first RAT network, further comprising: sending, by the control node, an instruction message to the UE, wherein the instruction message is used to instruct the UE to enter the dormant period of the first C-DRX cycle by disabling an active-period timer and a second inactive-period timer, wherein the active-period timer and the second inactive-period timer are used to perform timing for the UE in the active period of the first C-DRX cycle. sending, by a control node in a first RAT network, a measurement control message to a user equipment, UE, in the first RAT network, wherein each connected-discontinuous reception, C-DRX, cycle comprises a dormant period and an active period, and the measurement control message is used to instruct the UE to measure signal quality of a second RAT network in a dormant period of a first C-DRX cycle; the method further comprises: disabling, by the control node, a first inactive-period timer, wherein the first inactive-period timer is used to perform timing for the control node in an active period of the first C-DRX cycle; and performing, by the control node, downlink transmission for the UE in the active period of the first C-DRX cycle; after the sending, by a control node in a first RAT network, a measurement control message to UE in the first RAT network, further comprising: sending, by the control node, an instruction message to the UE, wherein the instruction message is used to instruct the UE to enter the dormant period of the first C-DRX cycle by disabling an active-period timer and a second inactive-period timer, wherein the active-period timer and the second inactive-period timer are used to perform timing for the UE in the active period of the first C-DRX cycle. disabling, by the control node, a first inactive-period timer, wherein the first inactive-period timer is used to perform timing for the control node in an active period of the first C-DRX cycle; and performing, by the control node, downlink transmission for the UE in the active period of the first C-DRX cycle; after the sending, by a control node in a first RAT network, a measurement control message to UE in the first RAT network, further comprising: sending, by the control node, an instruction message to the UE, wherein the instruction message is used to instruct the UE to enter the dormant period of the first C-DRX cycle by disabling an active-period timer and a second inactive-period timer, wherein the active-period timer and the second inactive-period timer are used to perform timing for the UE in the active period of the first C-DRX cycle.