Nano TiO2 with high photocatalytic activity was prepared by microwave-assisted hydrothermal method using butyl titanate as the raw material. It was characterized by XRD, TEM and verified by photobleaching performance of indicator films through UV-VIS diffuse reflectance spectroscopy. Results showed that TiO2 prepared by microwave-assisted hydrothermal method got more characteristic diffraction peak intensity and grew more regularly compared with conventional hydrothermal method under the same conditions. Oxygen indicator ink was constituted by using TiO2 as the photocatalyst, glycerol, MB as the oxidation reduction dye and HEC as the encapsulating material, which was completely bleached by UVA within 3 min and restored within 30 min in the air, retaining its original activity after repetition of 10 times of photobleaching and color restoration by spectral analysis. With the widespread use of ink jet printing, the ink oxygen indicator ink or label on the inner layer could be applied in food packaging industry with good prospect.