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The copper salt accelerated acetate salt spray test (CASS method) is an improved version of the neutral salt spray test. By acidifying it with acetic acid in a sodium chloride solution and adding copper chloride to increase the corrosion rate and effectiveness on certain metal coatings, good results were achieved, with the corrosion of cathodic coatings on steel substrates resembling that in actual environments. Compared with the neutral salt spray test, the CASS method not only has an accelerated corrosion rate but also offers better reproducibility; therefore, it is gradually replacing the neutral salt spray test for testing the corrosion resistance of cathodic coatings. This method is applicable to the corrosion resistance testing of cathodic coatings (copper, nickel, chromium coatings, etc.) on steel substrates, as well as anodized films on aluminum or aluminum alloys. The components of the solution used to accelerate the acetate salt spray test with copper salts are: sodium chloride (NaCl) at 50±5 g/L, copper chloride (CuCl2·H2O) at 0.26±0.02 g/L, and a pH value of 3.2±0.1 (adjusted using acetic acid). The testing equipment is roughly the same as that used for salt spray testing, except that higher requirements are placed on the box’s resistance to high temperatures (50±1℃). Currently, in addition to equipment specifically designed for CASS tests, there is also equipment that can be used for salt spray tests. Except that the test temperature is 50±1°C, the other conditions are the same as those of the salt spray test.