The invention relates to a hot-dipping alloy specially used for coating layers of titanium alloy part surfaces, wherein the hot-dipping alloy consists of 8-24 percent of silicon, 1.2-3.1 percent of zinc, 0.02-0.5 percent rare earth elements, 0.5-3.2 percent of manganese content, 0.05-1 percent of ferrum, 1.0-2.0 percent of magnesium, 0.5-2.0 percent of chromium, 1-2 percent of nanometer oxide particle reinforcing agent, and the balance of aluminum and inevitable impurities, wherein the nanometer oxide particle reinforcing agent is TiO2 and/or CeO2. The coating layers which have high corrosion-resistance and abrasion-resistance and can be bonded with matrix metallurgy can be formed on the titanium alloy surfaces.