Objective To preliminarily explore the application of Ni-W alloy coating in QT-900 coiled tubing. Methods Ni-W alloy coating was deposited on the surface of QT-900 coiled tubing by DC electrodeposition. An oilfield corrosion environment was simulated by high temperature and high pressure corrosion tests. The effect of Ni-W alloy coating on coiled tubing was studied by comparing the corrosion resistance of Ni-W alloy coating and coiled tubing using analysis methods such as microscopy, SEM and EDS. The effect of Ni-W alloy coating on the corrosion resistance of oil tubing in CO2 medium was studied. Results Ni-W alloy coating mainly consisted of Ni and W elements, and the Fe and Mn contents were low. The average thickness of the coating was 55 μm. The uniform corrosion rate of Ni-W alloy coating was 0. 0160 mm/ a at 60℃, with a CO2 partial pressure of 1. 07 MPa and a tensile stress of 439 MPa, which was 1 /40 of that of the ordinary coiled tubing. The corrosion rate belonged to slight corrosion. Conclusion Ni-W alloy coating had a good resistance to CO2 corrosion.