Nowadays

for its capability in tracking thousands of macro particles

PIC coding has to become an im-portant tool for studying beam physics. In this paper the PIC method for the accelerator’s electron-optics simulation is introduced; 1.2 MW accelerator’s electron-optical-system made in Chinese Academy of Engineering Physics has also been simulated using static and dynamic methods. Results show that as the intensity of the beam flux increases

the radius of the beam firstly decreases and then increases gradually. When the beam flux is around 250 mA

the beam radius reaches a minimum value

and the results of these two methods differentiate with each other by 7%; however

the beam radius of 500 mA beam flux reaches to that of small beam flux

and the results of these two methods differ from each other by 29%.