As the society and economy move forward, energy and environmental problems have attracted extensive attention. Hydrogen energy is considered the ideal clean energy in the 21st century due to its high energy density, pollution?free attribute, abundant reserves, and wide application. As a clean production technology, hydrogen production by water electrolysis has developed vigorously under the goals of carbon peak and carbon neutrality. The key challenge lies in the development of high?performance electrocatalysts for the hydrogen evolution reaction (HER) to reduce the overpotential of water splitting. This paper reviewed the current mainstream hydrogen production technologies by water electrolysis in detail and analyzed the characteristics and advantages and disadvantages of each technology. Moreover,it summarized the research progress of HER catalysts and predicted the development directions of the hydrogen production technology by water electrolysis and its electrocatalysts.