Abstract: TiO₂/Bi₂WO₆ heterojunction composite is one of the most promising visible-light derived photocatalysts. Its photocatalytic performance mainly depends on the interface structure and micro-morphology. However, it is a great challenge to control and tailor the micro-morphology and interface structure of TiO₂/Bi₂WO₆ heterojunction. Herein, TiO₂/Bi₂WO₆ heterojunction was synthesized by defect induced hetero-growth method. The influences of the defect size and distribution density, located on TiO₂ nanobelts substrate, on the microstructure and photocatalytic activity of the TiO₂/Bi₂WO₆ composites was further investigated. The results indicate that the corroding temperature and retention time are the key to modify the defect size and distribution density on the substrates. The defect size and distribution density are 26 nm and 12 per μm² respectively, which facilitate to construct TiO₂/Bi₂WO₆ heterojunction composites with well interface structure. With the as-prepared TiO₂/Bi₂WO₆ heterojunction as photocatalyst under visible light, rhodamine B (RhB) and methylene blue (MB) can be completely photodegraded after irradiation for 12 min and 20 min respectively, and the degradation percentage of phenol also is reached 43.8% after 70 min of irradiation.