Objective To perform surface modification for clinical orthodontic stainless steel arch wires, compare surface components, surface patterns, mechanical properties, corrosion resistance, and antibacterial property between modified and unmodified stainless steel arch wires, and provide reference for the clinical application of stainless steel arch wires. Methods Stainless steel arch wires with the size of 0.019 inch (0.48)×0.025 inch(0.64 mm) were used. Polydopamine was used as the medium and carboxymethyl chitosan (CMC) was covalently grafted on the surface of stainless steel arch wires. Surface components were analyzed and surface patterns were observed by energy dispersive X-ray analyzer and scanning electron microscope. Microhardness tester was used to test hardness of stainless steel arch wires. Electrochemical working station (CHI660C) was used to measure the corrosion resistance. WST reagent was used to detect the antibacterial property. Results The surface of modified stainless steel arch wires contained C, N, O, Si, Cr, Mn, and Fe, while the surface of unmodified stainless steel arch wires only contained Si, Cr, Mn, and Fe. The difference in microhardness between modified and unmodified stainless steel arch wires was not statistically significant. The corrosion resistance and antibacterial property of modified stainless steel arch wires were greater as compared with unmodified stainless steel arch wires. Conclusion The modification of orthodontic arch wires via polydopamine surface and grafted CMC can mitigate corrosion and inhibit the growth of bacteria without compromising the mechanical performance, so as to benefit the orthodontic application.