The present invention relates to a switch control device, a multi-channel converter including the same, and a switch control method thereof. A multi-channel converter includes at least two converters, and each converter includes at least one power switch. The multi-channel converter supplies the sum of the output power of at least two converters to the load. The switch control device generates at least two gate signals switching operation of each of at least one power switch of at least two converters. The switch control device modulates a switching frequency of at least one power switch according to the load, determines the number of phases of the multi-channel converter according to the load, and generates a gate signal for the phase difference corresponding to the number of the determined phases between at least two gate signals to be generated.