本文描述了静电偏转孔道入口间隙及其位置等有关物理参数的确定原则。以单粒子运动理论为基础对静电偏转系统进行设计。最后,还讨论了粒子束在该孔道内相空间的变化。 This paper describes the principle of determining the relative physical parameters such as the entrance gap of electrostatic deflection tunnel and its location. Electrostatic deflection system is designed on the basis of single particle motion theory. Finally, the change of particle beam in the phase space is also discussed.