A method of controlling a terminal and an associated ancillary device are disclosed. The method includes: the ancillary device receiving information of an unprocessed event from the terminal, wherein the information contains a type and a serial number of the unprocessed event; receiving a predefined operation from a user and producing a tag for the unprocessed event accordingly, wherein the tag contains the type and serial number of the unprocessed event; and sending the tag to the terminal, so that the terminal generating a corresponding notification message according to the tag. Thus, the unprocessed event present on the terminal can be directly processed through the ancillary device, and the terminal can eventually generate a notification message to notify the user of the unprocessed event.