Abstract: The doubly charged Higgs bosons H₅^±± are the typical particles predicted in the Georgi-Machacek model and their decay modes depend on the magnitude of the triplet vacuum expectation value.Their pair production process at the ILC was studied.The numerical results showed that, as long as the doubly charged Higgs bosons masses are not too heavy, their possible signals might be detected in future ILC experiments. A simply phenomenological analysis for the signal and the relevant SM backgrounds is also given.