There is provided a head hair dyeing method using a two-part hair dye composition which contains: a first part containing a first part stock solution and a propellant, the first part stock solution containing an alkali agent and a surfactant; a second part containing a second part stock solution and a propellant, the second part stock solution containing hydrogen peroxide and a surfactant; and two aerosol containers for respectively discharging the first part and the second part as foam, the method including respectively discharging the first part and the second part as foam from the containers, applying the foam mixture to the head hair, and then re-foaming the mixture on the head hair.