Aimed at improving wear, corrosion resistance and enhancing fire retardance, several plasma surface treating methods on titanium alloys had been presented, which included add-arc glow hydrogen-free carburizing plasma depositing on titanium alloy, double glow plasma hydrogen-free carburizing on titanium alloy, double glow Mo diffusing,  double glow Cr diffusing, double glow Cu diffusing. The results showed that gradient layer had formed on the titanium alloys surface, that was of great significance on wear, corrosion resistance and fire burning resistance.