Choosing the BFEL parameters, we simulated the effects on FEL spontaneous spectrum due to field errors, and obtained the acceptable condition of all kinds of field errors in undulator.

• 并讨论了各种场误差对自由电子激光器自发辐射谱的影响，选择北京自由电子激光器(BFEL)参数，进行模拟，最后确定出各种场误差的可接受条件。