提出一种基于一维线衍射光栅的焦斑重构和远场测量新方法，从理论上分析了新方法在拓展测量仪器动态范围、提取远场焦斑高频旁瓣信息的有效性及方法的适用条件。基于实验室现有的一套远场测量系统平台及自行设计的一维线衍射光栅，以远场环围能量(PIB)曲线作为检验新方法有效性的指标，通过数值仿真和实验相结合考察了新方法的有效性，并从准确测量远场焦斑质量的角度探讨了不同减阈值的去噪方式对焦斑重构结果的影响，对结果进行了分析讨论。

A new method of the reconstruction of focal spot and far-field focal spot measurement based on the diffraction grating is proposed, the validity of new method in expanding the measurement dynamic range and extracting the focal spot side lobe data is analyzed and the application condition is given in theory. According to the far-field spot measurement system available in laboratory and 1-D linear diffraction grating designed, power in the bucket (PIB) curve is taken as the measure of the validity of new method, the applicability of this new method is investigated by numerical simulation and experiment, in which the influence of the choice of the threshold on the results is discussed from the view of accurately calculating focal spot quality. The results are discussed and analyzed.