To improve the performance of synchronization control of coordinated motion in the networked computer numerical control (CNC) system, a periodic communication plan which combined the point-to-point communication with the lumped-frame communication in the ring network was proposed to make the master to access the feedback messages of all axes timely. The corresponding position synchronization algorithm and motion message estimating algorithm were proposed. Meanwhile, the stability proof of the position synchronization controller designed according to the algorithms was conducted. Finally, experiment results showed that the root mean square errors (RMSE) of the position synchronization controller corresponding to the communication plan were reduced by 49.270% than those of the standard proportional-derivative (PD) controller. The results indicate that the position synchronization controller corresponding to the communication plan has good synchronization performance, which has positive meaning to further improve the performance of synchronization control in networked CNC system.