The γ-MnO₂@CNT catalyst was prepared by in situ solid phase synthesis and first applied into sodium-air batteries（SABs）. The initial discharge specific capacity of SABs with γ-MnO₂@CNT catalyst can reach 8804 m A h g^-1 and the overpotential gap is only 140 mV, which is better than the batteries that is catalyzed by α-MnO₂@CNT and pure CNT. Besides, the batteries also exhibit excellent cycle performance, which can keep relatively stable for 246 cycles at 500 mA g^-1 and 140 cycles at1000 mA g^-1.