The invention discloses a preparation method of an air permeable electrode. The preparation method comprises the following steps that (1), a porous titanium substrate is made; (2), the surface of the titanium substrate is treated; (3), the precursor is deposited, specifically, the titanium substrate is placed in an ethanol aqueous solution, containing titanium dichloride, ruthenium chloride and iridium chloride, with the pH value being 1-5 to be deposited; (4), electrolyzing is conducted; and (5), sintering is conducted, and the air permeable electrode is obtained. The obtained air permeable electrode is large in effective specific area, the NaClO yield of the air permeable electrode is much higher than that of a traditional electrode, salt consumption and electricity consumption are low, and energy saving and emission reduction are achieved.