Exploring effective oxygen reduction reaction (ORR) electrocatalysts is crucial for progress in solid-state alkaline zinc-air batteries (ZAB). In this paper, silver-manganese dioxide-carbon nanotubes (SMC) ternary composites, which function as Electrocatalyst for air Electrodes, was produced via the pyrolysis of silver permanganate under microwave irradiation in one step. A scanning electron microscope (SEM), X-ray diffraction (XRD), and an energy dispersion spectrometer (EDS) have consistently determined that SMC consists of silver and alpha-manganese dioxide, which anchored on the surface of CNTs. Through polarization and chronoamperometery curves, the electrocatalytic activity of SMC for ORR was examined. The results reveal that SMC has higher catalytic activity than the chemically produced electrocatalyst for ORR in alkaline condition. Finally, a solid-state zinc-air cell with an electrocatalyst was constructed and tested. Constant current discharge curve of the zinc-air cell with SMC has a long discharge voltage plateau and a 60.03 mAh capacity at 30 mA · cm−2 . The mechanism of improvement in electrocatalytic activity was also discussed. In a summary, the strategy described in this study and the electrocatalyst produced can be regarded as an effective method for making a robust oxygen reduction catalyst toward solid-state zinc-air batteries.