Abstract: Electron optical software Egun is a professional software used to calculate the electron trajectories in two-dimensional electrostatic field and static magnetic field. It is successful in designing Pierce electron gun and other electron optical systems and has a fast calculation speed. So far, it is still widely used. However, in the simulation of vacuum electronic devices, the evaluation of the electron laminar properties of the designed electron optical system can only judge the laminar properties through the observation of the electron trajectories. The software does not give quantitative evaluation index parameters, and the modification of design parameters is very cumbersome and lacks an automatic optimization function, which greatly affects the exertion of the advantages of Egun. In this paper, two evaluation indexes, crossover rate and volatility, are proposed to measure the electron laminar properties,and a set of self-optimizing software is developed. The simulation results show that the two indexes of crossover rate and volatility can accurately and quantitatively evaluate the electron laminar properties; when the electron trajectories crossover rate is less than 3% and the volatility is less than 30%, the electron laminar properties can meet the design requirements. The evaluation index of electron laminar properties-crossover rate and volatility also provides target evaluation parameters for the automatic optimization of the electron optical system to find the best parameter value, which will greatly reduce the consumption of personnel and material resources.