Device and method of controlling a traffic light on the basis of an analysis result of a broadcast signal transmitted via a broadcast network are provided. The traffic light control device controlling signal light change of a traffic light, includes: a broadcast signal receiving unit that receives a broadcast signal emitted from a traffic control center via a broadcast network; and a traffic light control unit that determines an offset time from a reference traffic light on the basis of an analysis result of the broadcast signal and that outputs a control signal for controlling the light change of a control target traffic light so that a time point which lags by the determined offset time from a signal light display start time point of the reference traffic light is matched with a signal light display start time point of the control target traffic light.