<p>The influence mechanism of laser power on corrosion resistance of laser-arc hybrid welded joints of Ti-containing weathering steel was studied. The results show that, except for the samples at the laser power of 1500W, the amount of corrosion of the specimen increases with the laser power, that is, the corrosion resistance decreases with the increase of the laser power. According to the macroscopic corrosion morphology, the thickness of the rust layer on the sample surface increases with the increase of laser power. In addition, the corrosion degree of heat-affected zone (HAZ) and weld metal (WM) is more serious compared with the base metal (BM). After cleaning, the microstructure in the WM at the laser power of 2000W is seriously corroded, and more small corrosion pits occurs. However, the other samples are corroded lightly. When the laser power increases, the surfaces of samples are more seriously corroded, i.e., more pits can be found and the corresponding corrosion resistance decreases. The main form of corrosion in the BM and HAZ is intercrystalline corrosion, while it transforms into intercrystalline corrosion and point corrosion in the WM. During the corrosion process, titanium element can form stable oxides, resulting in the change in the corrosion form and corrosion resistance of weathering steel welded joints. The results provide the experimental basis for the corrosion properties of Ti-containing weathering steel.</p> Graphical Abstract <p></p>