To resolve the problem of clock synchronization for power electronics distributed control system, a distributed control topology based on Ethernet ring is proposed. A clock synchronization method which is feasible and easy to achieve is presented in detail. The synchronization method which includes all-synchronization part and self-synchronization part can compensate the initial offset compensation, the propagation delay compensation and the dynamic drift compensation of master and slaves. Distributed control system based on DSP and FPGA is built. The feasibleness in engineering of the topology and clock synchronization method is verified by the experiments and it gets the accuracy within 15ns between master and slaves of the experimental system. Aiming at the inadequacies, countermeasures are taken to improve the clock synchronization accuracy.