As an environmentally friendly energy technology, direct methanol fuel cells (DMFCs) meet the needs of sustainable development. Herein, novel dicyanamide anion-based (N(CN)2–) ionic liquid (IL)-functionalized reduced graphene oxide (rGO)-supported Pt catalysts are synthesized via a facile one-pot room temperature reduction method, which show a boost in methanol oxidation performance compared with Pt/rGO. The mass activities of the as-prepared Pt/emimN(CN)2/rGO (863.6 mA mg–1Pt) and Pt/epyN(CN)2/rGO (524.9 mA mg–1Pt) are about five and three times higher than that of Pt/rGO (178.6 mA mg–1Pt), and about six and four times higher than that of Pt/C (140.2 mA mg–1Pt), respectively. The participation of ILs significantly improves the CO poisoning resistance, stability, and activity for methanol oxidation of catalysts. The relationship between the structures and conductivities of diverse ILs and the performance of Pt catalysts are studied systematically. These findings may offer a promising prospect of ILs in DMFCs.