The internal electron transport capacity of the semiconductor directly affects whether there is a sufficient number of photogenerated electrons involved in the catalytic reaction process, thus determining the photocatalytic efficiency. Indium tin oxide (ITO), as an excellent conductive material, has convenient internal electron transport and can be used as a good photocatalyst directly. In this paper, ITO films on three different conductive substrates were prepared by DC sputtering method, and the crystallization and appearance of each sample were compared. Different substrates affect the energy band position of catalyst. The performance of photocatalytic CO2 reduction was tested. We found that ITO films grown on carbon cloth (CC) substrate have good photocatalytic properties. The atmosphere ratio in the preparation process also has a certain influence on the performance of the sample. Compared with ITO conductive glass widely used in the market, our improved ITO film has better photocatalytic properties and practicability. This work provides a certain reference for the application of ITO in the field of photocatalysis.