Herein, Al2O3–ZrO2 multiphase ceramics with a eutectic molar ratio were prepared using the flash sintering technique at 1200 °C in 2 min. The samples were divided into two regions according to the microscopic morphology: multiphase ceramics zone and eutectic ceramics zone. The multiphase ceramics zone uniformly distributed irregular Al2O3 and ZrO2 phases. The eutectic zone presented typical eutectic morphology, where different morphologies of ZrO2 was uniformly embedded in the Al2O3 matrix, mainly showing fine lamellar, rod-like and irregular network morphology. Overall, flash sintering is a promising route to prepare high-performance multiphase ceramics.