为了提高弹性光网络的性能，提出一种时频域及阻塞门限联合触发的周期碎片整理(PDT-TFDBT)策略，该策略在触发条件方面采用改进碎片化指数的阻塞延迟触发机制，减少未阻塞时进行无效整理的负载量；在整理顺序方面综合考虑业务的时域和频域特征，合理分配业务的重构顺序，同时引入启发式深度学习辅助的路由及频谱分配(DKA-RSA)算法。仿真结果表明，PDT-TFDBT策略不仅可以减少重构业务数量和频谱碎片，而且进一步降低了业务阻塞率，提高了频谱利用率。

In order to improve the performance of elastic optical networks, a combined time-frequency domain and blocking threshold triggered periodic defragmentation(PDT-TFDBT) strategy is proposed. In this strategy, the blocking delay triggering mechanism with improved fragmentation index is adopted to reduce the load of ineffective defragmentation in non-blocking conditions. In terms of sorting order, the time domain and frequency domain characteristics of services are comprehensively considered, and the reconfiguration order of services is reasonably allocated. At the same time, the heuristic deep learning-assisted routing and spectrum allocation(DKA-RSA) algorithm is introduced. The simulation results show that PDT-TFDBT strategy can not only reduce the number of reconstructed traffic and spectrum fragmentation, but also further reduce the traffic blocking rate and improve the spectrum utilization rate.