Abstract: Producing ammonia, methanol, and other chemical products from "green hydrogen", essentially from renewable energy-based water electrolysis, is regarded as a key technological route toward the admittance of new energy and the decarbonization of the electrical power and chemical industry. Green hydrogen-based chemical engineering (GHCE) technology involves a deep cross between multiple disciplines. Current review papers on green hydrogen mainly focus on hydrogen production; therefore, a review on the utilization of green hydrogen coupled with the downstream chemical industry is still in need. To fill this gap, this paper first summarizes the main technical characteristics of the components in the GHCE system. Then the research status of the GHCE technology is summarized from two aspects, i.e., the GHCE system and power system integration. Shortcomings of the current researches are analyzed. Finally, research directions are prospected, including design and flexible regulation of large-scale hydrogen production, flexibility modeling of the chemical synthesis process, and analysis and control of the GHCE system to participate in power system balancing. Requirements on key supporting systems are proposed.