Single-crystal superalloys serve as the pivotal materials for blades and vanes of aeroengines and industrial gas turbines, as they display superior capability at high-temperature, complex-stress, and oxidative environments with microstructural stability balanced with excellent process performance. Furthermore, these alloys exhibit complex compositions and are associated with high costs, while their design methodologies remain relatively underdeveloped, they exhibit complicate deformation mechanism and manufacture process. Hence, much effort is paid to the related research on single crystal superalloy, and many results are obtained based on the new methods and new techniques. This article provides a comprehensive review of the recent advancements in alloy development, design methods, deformation mechanisms and fabrication processes. Additionally, it offers a brief overview of future research directions for single crystal superalloys and potential alternative materials.