为了研究高次谐波极紫外阿秒脉冲产生过程中的谐波相位匹配问题，基于光场电离高次谐波产生过程3步分析模型得出了高次谐波产生过程的理论描述解析式，并以此分析了阿秒脉冲产生过程中的高次谐波本征原子相位。由研究可知，除最高阶谐波外，对同一阶高次谐波产生有贡献的电子均有两类——长轨迹电子和短轨迹电子，各高次谐波长轨迹电子产生的谐波谱相之间几乎不存在线性关系，而短轨迹电子产生的高次谐波谱相之间则存在着良好的线性关系。结果表明，抑制各谐波长轨迹电子有助于产生更小脉宽阿秒脉冲。此结果对极紫外阿秒脉冲产生实验中的高次谐波相位匹配有重要的参考价值。

In order to analyze the phase matching of extreme ultraviolet high harmonics in the process of attosecond pulses generation, the analytic expressions were achieved based on the three-step analysis model for optical field ionization high-harmonic generation(HHG), and the harmonic spectral phase in the process of attosecond pulse generation was analyzed. It was found that, except the highest order harmonic, the spectral phase contribution of each harmonic consists of two sources of long trajectory electrons and short ones, and that, unlike the generated harmonics by the former, the spectral phase of those harmonics from the latter has regular phase relation among each other. The final conclusion is drawn that suppressing the long trajectory electrons can reduce the pulse width of attosecond pulses, which is of great significance to the issue of high harmonic phase matching in generation of attosecond pulses.