A method of recovering a synchronization detection error according to an embodiment includes: determining whether a base station signal input to a head-end device is detected; determining whether a head-end signal output from the head-end device, which is obtained by processing the base station signal by the head-end device, is detected by a lower device of the head-end device; determining whether synchronization of the head-end signal is detected based on the head-end signal input to the lower device; and changing a set frequency band or performing automatic gain control of the head-end device based on whether the base station signal is detected, whether the head-end signal is detected, and whether the synchronization of the head-end signal is detected