详细介绍了用于北京自由电子激光器（ＢＦＥＬ）的多腔热阴极微波电子枪的物理设计以及模拟计算结果，给出了出束及热测实验研究结果．该微波电子枪采用双周期轴耦合驻波加速结构，由四个加速腔组成，工作在π／２模，工作频率为２８５６ＭＨｚ．该枪在设计中采用了缩短首腔以及增加腔间漂移段等设计思想，大大减小了电子反轰功率，并有效地调节了电子束团的纵向特性 The physical design and simulation results of the multi-cavity hot cathode microwave electron gun used in Beijing Free Electron Laser (BFEL) are introduced in detail. The results of the beam-out and thermal experiment are given. The microwave electron gun adopts a double-cycle axis coupled standing wave accelerating structure and is composed of four accelerating cavities. The working mode is π / 2 mode and the working frequency is 2856MHz. The design of the gun used in the design to shorten the first cavity and increase the cavity drift stage, etc., greatly reducing the electronic anti-booming power, and effectively adjust the longitudinal properties of the electron bunch