在单光子探测峰值扫描测量法的基础上,设计了峰值时延跟踪系统。通过扫描前一次峰值位置附近的时间范围,统计比较出各测量点计数率的最大值,实时获得新的峰值位置,从而实现了温度剧烈变化环境下125 km光纤链路上的峰值实时跟踪实验。针对扫描步长大带来的精度受限问题,在峰值判定时引入多项式拟合方法,提高了系统的准确度。通过设计单双程实时测量比对实验,证明了通过峰值时延跟踪系统测得的光脉冲传输时间的准确度优于雪崩光电二极管直接测量法所得结果。 Based on the single-photon detection peak-scan method, a peak-delay tracking system is designed. By scanning the time range around the previous peak position, the maximum count rate of each measurement point is statistically compared to obtain the new peak position in real time, so as to realize the real-time peak-to-peak tracking experiment on the 125 km optical fiber link under the severe temperature change. In view of the limited precision brought by the large scanning step, polynomial fitting method is introduced in peak judgment, which improves the system’s accuracy. Through the design of single-pass real-time measurement comparison experiments, it is proved that the accuracy of the optical pulse transmission time measured by the peak time delay tracking system is superior to that obtained by the avalanche photodiode direct measurement method.