Effective water chemistry technology can inhibit the radiolysis of primary coolants and material corrosion in pressurized water reactors (PWRs). Research and operational experience suggest that methanol is a potential additive for the coolant transformation of PWRs. However, due to a lack of comprehensive understanding regarding the behavior and mechanism of methanol radiolysis in primary circuit scenarios, supporting methanol-based water chemistry control is challenging. This study initially outlines the importance of methanol radiolysis. It then summarizes global research progress on methanol radiolysis and its aqueous solution. Additionally, it discusses the yield of methanol radiolysis products and free-radical reactions at room temperature, as well as the radiolysis of methanol aqueous solutions under primary circuit conditions and its impact on material corrosion, are then discussed in detail. Finally, the study offers suggestions for future research on the radiolysis of methanol aqueous solutions.