采用经典公式、平均场理论和脉冲展宽模型研究时间展宽分幅管的物理和技术时间分辨率。分析电子初能、阴极偏置、阴极脉冲斜率和漂移距离等参数对时间分辨率的影响。讨论时间分辨处于皮秒级和亚皮秒级时物理和技术时间分辨所起的作用,并探讨实现亚皮秒级时间分辨的可能性。研究结果表明：物理和技术时间分辨相互制约，当像管时间分辨处于5 ps量级时，技术时间分辨决定像管时间分辨；当像管时间分辨提升到亚皮秒量级时，物理和技术时间分辨处于同量级，像管时间分辨由两者共同决定。

The physical and technology temporal resolution of pulse dilation frame tube were studied by the classic formula, the mean field theory and the pulse dilation model. The influence of the parameters on temporal resolution was analyzed, which are the initial energy, the cathode biased, the ramp pulse and the drift distance, etc. The effect of the physical and technology temporal resolution in picosecond (ps) and the sub-ps time scale and the possibility of achieving sub-ps of temporal resolution were discussed. The results show that the physical and technology temporal resolution are restricted each other. The temporal resolution of tube is decided by the technology temporal resolution when temporal resolution is 5 ps time scale. The temporal resolution of tube is decided by the physical and technology temporal resolution when the temporal resolution is sub-ps time scale.