采用自由基浓度起伏理论结合光镊集聚效应，理论研究了飞秒激光双光子加工的线宽问题。根据双光子光聚合过程中自由基浓度随时间变化的关系，考虑光镊效应对自由基分布范围的影响，得到了飞秒激光双光子加工线宽的表达式。研究了线宽随扫描速度与激光功率的变化关系，并讨论了不同光引发剂对线宽的影响。得到了以自由基浓度起伏为基础，并考虑光镊效应的双光子加工线宽表达式，该结果与实验结果相符。研究结果为飞秒激光双光子加工的研究提供了新的思路，为光镊集聚效应对线宽影响的实验研究提供了理论依据。

In this paper, the linewidth of femtosecond laser two-photon polymerization is studied by the theory of free radical density and the effect of optical tweezers. Based on the relationship between free radical density and time in the process of two-photon polymerization, the expression of linewidth of two-photon femtosecond laser processing is deduced considering the effect of optical tweezers. The relationship of linewidth with scanning speed and laser power is studied and the influence of different light initiators on the linewidth is also discussed. The theoreticial result agrees well with the experimental one in the literature. The result of this paper gives a new idea for the study of femtosecond laser two-photon processing, and provides a theoretical formula for the study of the influence of optical tweezers on linewidth.