A pen cap for operating a digital terminal, comprising a main body (1) sleevable on one end of a pen. The main body (1) is provided with a button (2). A battery and a Bluetooth module for data exchange are provided within the main body (1). The main body (1) of the pen cap for a digital terminal enables data exchange by means of a connection to a digital terminal via Bluetooth. During use, a user can input a signal to the digital terminal by directly pushing a button on the main body (1), thus eliminating the need to directly contact the digital terminal, and minimizing influences on the digital terminal. In addition, the pen cap for a digital terminal can be fitted to a pen as a normal pen cap, thus providing portability.