Green hydrogen has gained substantial support from countries around the world, it is known as the future fuel source because of its capacity of reducing the greenhouse gas (GHG) emissions. Water electrolysis is a sustainable and environmentally friendly method for producing green hydrogen, many technologies can be explored here such as: Proton exchange membrane electrolysis (PEM), alkaline electrolysis (AEL), and solid oxide electrolysis (SOEL). In this paper, the state of the art of optimizing water electrolysis process will be explored. In this regard, the paper aims to discuss optimization technics and how it can support the optimization of green hydrogen production, the appropriate method of each issue will be explored also. The high cost is the main challenge of green hydrogen, hence this paper reviews market trends and techno-economic drivers. This review could give to readers an overview of optimizing green hydrogen production using water electrolysis, contributing to the adoption of this technology in the future.