Aiming at the problem of clock data recovery during the transportation of beyond 100 Gbit/s services using Flexible Optical Network (FlexO) technology, this paper designs and implements a new clock data recovery solution based on phase-locked loop frequency synthesizer to transform OTUCn to n OTU4 service data. Within a certain frequency offset of the OTU4 service frequency point, the customer clock is quickly recovered, and the retiming of the OTU4 service data is realized. Simulation and actual measurement prove that this solution can effectively meet the clock recovery requirements in FlexO. The client-side clock jitter of real-time recovery is less than 1×10-6, and it can ensure the continuous and stable transportation of OTU4 business data of multiple channels to the next stage.