Hydrogen fuel produced by photovoltaic-eletrolyzer system is a solution to solve problem of global warming, air pollution and fossil fuel crisis. The efficiency of photovoltaic-electrolyzer system can be promoted by the optimal matching between photovoltaic modules and electrolyzer. Based on experimental test and mathematical model, a certain series–parallel connection of photovoltaic cells is determined to match with electrolyzer. The aim is to match the voltage and the maximum power output of the photovoltaic modules to the operating voltage of the electrolyzer. So some auxiliaries such as DC-DC converter, maximum power point (MPP) tracking unit can be omitted. Therefore, the cost and resistances in the circuit are greatly reduced.