A control method of a dryer according to an embodiment of the present invention in which a heat pump system is provided as a heat source for heating air supplied to a drum includes selecting one of a plurality of operation modes in which initial driving frequencies are different from one another and inputting a drying start command to the dryer by a user; checking an outer temperature and comparing the outer temperature with a preset reference temperature T by a control unit; performing the operation mode selected by the user by the control unit, in a case where the outer temperature is equal to or more than the reference temperature T; performing an operation mode in which the initial driving frequency of the compressor is the highest of the plurality of operation modes, in a case where the outer temperature is less than the reference temperature T.