To investigate the influence of deposition parameters on the crystal phase composition and bonding properties of DC reactive sputtered niobium oxide coatings, niobium oxide coatings were prepared on the surface of AZ31 magnesium alloy by DC reactive sputtering technique using different oxygen flow rates, powers and deposition time. The films were characterized by an X-ray diffractometer and X-ray photoelectron spectrometer, and the bonding force of the coatings was determined by a scratch meter. The results showed that when the oxygen flow rate was 0.5~3.0 mL/min, the power was 60~100 W, and the deposition time was 3~7 h, the deposition parameters did not affect the crystalline phase structure and chemical valence state of the niobium oxide coatings, while they had a significant impact on the bonding properties of the layers. The coating bonding decreased with increasing oxygen flow rate, and increased and then decreased with increasing sputtering. When the sputtering power was 80 W (sample W3) and the deposition time was 300 min (sample T3), the binding force of the coating was the largest, respectively.