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125km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。

The system of peak time delay tracking is designed, which bases on peak count rate scanning method for single photon detector. By scanning the time range near the previous peak position, a group of data can be compared to find the biggest value for determining the new peak position. It implements the peak of real-time tracking experiment during 125 km optical fiber in the environment of rapidly changing temperature. In order to solve the precision problem which is limited by the long step, the system introduces the polynomial fitting method to increase the accuracy. The accuracy of the light pulse transmission time obtained by peak time delay tracking system is superior to that obtained by avalanche photodiode directly measuring method, which is proved by the comparison experiment of single passing and double passing real-time measurements.