Abstract: A device for electrolyzing water includes pivots separately arranged on two ends of an insulating container, and a cylindrical cathode and a cylindrical anode are separately and respectively connected to the two pivots. The cathode and the anode are coaxial to the container and a plurality of through-holes are defined in sidewall of the anode and the cathode. A direct current (DC) source is provided to attach the two pivots so that the cathode and the anode are charged. A power source is provided to separately rotate the two pivots so as to rotate the anode and the cathode. The rotation velocity of the anode is different from that of cathode, thereby inducing a layer of dialytic film therebetween. Two input and output vents are separately and respectively defined in two ends of the container. An output vent is arranged on a side of the pivot connecting the anode so as to collect acidic electrolyzed water.