GB/T 20854-2025 "Accelerated test of cyclic corrosion of metals and alloys exposed to salt fog," dry "and" wet "conditions" is a key standard for the corrosion resistance evaluation of materials in our country. The standard was issued by the State Administration for Market Regulations and will be officially implemented on November 1, 2025, replacing the 2007 version of the standard. The new standard is equivalent to the ISO 14993:2018 international standard, and innovatively introduces the detection method of organic coating samples (Appendix C/D), optimizing the test solution configuration (4.1), spray pressure parameters (5.3) and cycle conditions (Table 1) and other core technical indicators. It is suitable for evaluating the corrosion resistance performance of metal materials in complex environments such as marine atmosphere, and provides standardized accelerated corrosion testing (ACT) solutions for aerospace, marine engineering and other fields.