The invention discloses a method for optimizing charge separation efficiency of a carrier conduction layer. The method comprises the steps of 1, ultrasonically cleaning a base material by using a cleaning agent, and drying after cleaning to obtain a transparent conductive substrate; and 2, conveying the transparent conductive substrate in the S1 into a deposition chamber, introducing oxygen and argon in a ratio of 1:6, controlling the total pressure to be 1 Pa, controlling the distance between a target and the transparent conductive substrate to be 8 cm, and depositing the carrier conduction layer for 15 min; and after the deposition is finished, feeding a sample tray into an etching chamber, and etching the transparent conductive substrate by adopting direct-current plasma. Compared withthe prior art, the method is simpler in process aspect, can be continuously prepared in combination with magnetron sputtering without increased excessive cost, and is economically feasible; in terms of performance, the area at the interface is increased, so that more carrier separation and transport channels are provided, electron-hole pair recombination at the interface is inhibited, and the photoelectrochemical performance of the sample is improved.