GB/T 2423.38-2021 "Environmental testing - Part 2: Test methods - Test R: Water test methods and guidance" was issued and implemented in 2021, replacing the old version and equivalently adopting international standards to ensure international mutual recognition of test results. This standard specifies various water test methods, including dripping water, spraying water, and immersion water, clearly defining test equipment parameters, operational procedures, and acceptance criteria. It covers simulation scenarios of water environments with different severity levels. The standard is applicable to electrical and electronic products, automotive electronics, outdoor equipment, and other products that may encounter water during transportation, storage, or use. Its core focus is to assess the waterproof performance of product enclosures and seals, verify functional integrity after exposure to water, provide technical support for IP protection rating certification, and establish a unified basis for product design and quality control.