Provided are a DC-DC converter driving device and a driving method thereof, the DC-DC converter driving device including an error detector configured to compare a first feedback voltage corresponding to a first output terminal with a first compensation reference voltage to generate a first error voltage, and configured to compare a second feedback voltage corresponding to a second output terminal with a second compensation reference voltage to generate a second error voltage, an interference detector configured to determine interference between the first and second output terminals on the basis of the first and second error voltages to generate an interference error voltage, and a reference voltage compensator configured to assign a weight to the interference error voltage to generate the first and second compensation reference voltages, and thus priorities are determined for outputs of the DC-DC converter and weights according thereto are assigned to reduce occurrence of cross-regulation.