In this study, the Zr2CN powder was fabricated using a carbothermal reduction method under a nitrogen (N2) atmosphere with nanometer m-ZrO2, micron-sized Ca-PSZ and nano-carbon black as raw materials. The product was characterized by X-ray diffractometry (XRD) and energy dispersive spectroscopy (EDS) under a scanning electron microscopy (SEM). The Zr2CN synthesis mechanism was analyzed. The results showed that the formation of Zr2CN phase was attributed to C, N diffusion, C–CO2–CO system equilibrium variation and ZrO2 decomposition; its formation primarily includes four stages of cyclical intersection (solid-gas diffusion and formation of high-temperature stable ZrO2, surface Zr2CN formation, ZrO2 partial decomposition and vapor deposition, inner layer Zr2CN formation and surface layer Zr2CN Oxidation). The four stages were cycled until the end of the ZrO2 formation of Zr2CN.