The disclosure discloses a method for sending trigger message to a Machine Type Communication (MTC) User Equipment (UE), including that: an MTC server sends the trigger message to an MTC InterWorking Function (MTC-IWF); the MTC-IWF packages the trigger message as a short message, and sends the short message to a serving node of the MTC UE via an interface T5; and after receiving the trigger message sent by the MTC-IWF via the short message, the serving node sends the MTC UE the trigger message via control signalling or a short message. The disclosure further discloses a system for sending the trigger message, and an MTC UE. With the disclosure, the trigger message can be sent to the MTC UE via an interface T5.