Depolarization of anode by sulfurous anhydride allows to reduce power inputs on hydrogen production in 1.5 times. The reason which prevents commercialization of this process is realization impossibility of industrial electrolysis current density because of SO2 feeding diffusion limitation to anodic catalytic layer. Pressure influence on water electrolysis process with depolarization anode by sulfurous anhydride in solid polymer electrolyte electrolyzers is examined.