A membraneless water electrolysis device for preparing beauty lotion is characterized by comprising a water container, a controllable electrolytic power supply and a membraneless electrolysis electrode assembly, wherein the membraneless electrolysis electrode assembly is soaked in water in the water container; the controllable electrolytic power supply supplies power to the membraneless electrolysis electrode assembly; raw water is electrolyzed through the clearance between different-polarity electrodes of the membraneless electrolysis electrode assembly; the membraneless electrolysis electrode assembly adopts a membraneless water electrolysis technology capable of effectively electrolyzing purified water or distilled water; the design of the membraneless electrolysis electrode assembly has the characteristics of reasonable relative small clearance between different-polarity electrodes gaps, reasonable relatively large area of electrode gaps, and proper water flowability in the electrode gaps during the water electrolysis process, so as to increase the probability of electrolysis of impurities and water molecules and the quantity of electrolyzed impurities and water molecules, and improve the water electrolysis efficiency to reach ORP and PH value and other indexes of the beauty lotion.