对贝塞尔光束和局域空心光束的轴上相位分布进行分析。用衍射理论分析了理想贝塞尔光束和用轴棱锥产生的贝塞尔光束的光强和相位变化，得知贝塞尔光束在轴上的相位呈周期性的锯齿状分布。由两束理想贝塞尔光束干涉得到的自成像局域空心光束轴上相位分布也呈锯齿状，但在光强为0的位置出现相位奇点。而仿真实验中自成像局域空心光束轴上光强最小位置处由于光强不为0，并没有出现相位奇点。研究结果对于用相位调制法产生暗域光强为0的局域空心光束具有指导意义。

Phases of Bessel beam and self-imaged bottle beam along propagation axis are analyzed. Phases of ideal Bessel beam and Bessel beam generated by axicon along propagation axis are periodic saw-toothed distribution after analysis with diffraction theory. And phase of self-imaged bottle beam generated by interference of two Bessel beams is also saw-toothed distribution, while phase singularity is found at the zero intensity position. In simulation experiment, the minimum intensity of self-imaged bottle beam on axis is not zero, therefore there is not phase singularity on axis. The result of research is valuable in generating self-imaged bottle beam by phase modulation, whose dark field is zero.