Abstract: The corrosive medium generated by coal-fired power boilers during operation will form oxide scale and corrosion products on the surface of welding joints, resulting in a decrease in joint strength. To improve the quality of welded joints in coal-fired power generation boilers and reduce the corrosion rate of welded joints, the laser-TIG composite welding process and corrosion performance test analysis of coal-fired power generation boilers are studied. The new type of ferritic heat-resistant steel SA213-T23 was selected. The laser-TIG composite welding process was adopted, with YAG solid-state pulsed laser and paraxial TIG arc as the heat sources. The laser power was set at 300W, 350W, 400W and 450W respectively for welding. After the welding was completed, the basic mechanical properties and corrosion resistance of the specimens were tested. The results show that moderately increasing the laser power can enhance the joint strength, and the basic mechanical properties of the weld seam can reach the optimal level at 400W. Moreover, in the tests of electrochemical corrosion, intergranular corrosion and immersion corrosion in different media of this laser power welding specimen, the corrosion potential of the 400W specimen was the highest and the corrosion current was the smallest. The self-corrosion current, self-corrosion potential and passivation current were all superior to those of other power specimens. Meanwhile, its mass loss is minimal and no cracks occur after bending. During the soaking process in H2S4O and NaOH solutions of different mass fractions, the corrosion rate of the 400W specimens remained the lowest all the time. Therefore, when the welding laser power is 400W, the quality of the welded joints of coal-fired power generation boilers can be effectively guaranteed.