The disclosure discloses a method for realizing user accessibility and a multi-mode terminal. A UE initiates, after a tracking area update (TAU) periodic timer of the UE expires, an update process to a mobile switching center/visitor location register (MSC/VLR) in the case that an idle mode signaling reduction (ISR) is activated and the UE resides in a global system for mobile communications/universal mobile telecommunication system (GSM/UMTS). The disclosure improves user experience.