A device for measuring the emission angle of a particle beam. The device includes a shell, a data acquisition board, a data collector, a data processor and a data synchronization display. The shell is hollow tubular. The data acquisition board is fixed to the front end of the shell. The data collector and the data processor are fixed together and fixed to the back end of the shell. The data collected by the data acquisition board is transmitted to the data collector through the data line collector, and the data processor transmits the processed data to the data synchronization display. The ion accelerator to be measured is located in front of the data acquisition board, and the particles emitted by the ion accelerator bombard the front of the data acquisition board. The data acquisition board comprises an insulating ring, an array insulating board and a pressure sensor.