Method and system for controlling activation of ISR (Idle mode Signaling Reduction) and UE (user equipment)

The invention discloses a method and system for controlling the activation of ISR (Idle mode Signaling Reduction) and UE (user equipment). The method comprises the following steps of: carrying out the combination of TAU (Tracking Area Update) and LAU (Location Area Update) by the UE; activating the ISR or keeping the ISR not activated under the condition of meeting preset conditions, wherein the preset conditions include: the result of the combination of TAU and LAU is as follows: only the combination of TAU and LAU of SMS (Short Message Service) over SGs (Serving Gateways) succeeds, and the UE needs to support a preset service; and the preset service comprises other CS (Circuit Switching) services except for the SMS. The invention ensures that the UE can be called when the CS services such as speech calling and the like are carried out.