The invention discloses a gold and silver surface anti-oxidation and anti-color-change protecting agent and a preparation method and application thereof, and belongs to the technical field of gold andsilver plating layer protecting agents. The protecting agent comprises the following components in parts by weight: 15-30 parts of color change preventing agents, 10-15 parts of film forming agents,3-8 parts of
alcohol ether solvents, 30-50 parts of emulsifying agents, 2-5 parts of
benzethonium chloride, 5-10 parts of
carboxylic acid type deoxidants, 1-3 parts of
corrosion inhibitors, 0.5-1 partof antioxidants, 1-3 parts of brightening agents, and 5-20 parts of water. The prepared protecting agent can form double
layers of protecting films to effectively prevent oxidation of gold and silverplating
layers by air and
corrosion by acid and alkali; meanwhile, the
surface corrosion and color change resistance of the plating
layers is improved; the brightness of the plating layers is improved; the performances of higher brightness and efficiency are given to the plating layers; the protecting agent also can be applied to surface protection of
copper substrates, and the effect can rival
chromium salt protecting films; the
copper surface colors can be not changed for a long time; the effect of low poison is achieved; and the treatment process is simple.