The ASTM G9-07 (2020) standard provides a test method for testing the water permeability of insulating coatings for pipelines. The method evaluates the insulation performance and deterioration rate of coatings by monitoring the penetration of moisture in the coating material. The test data reflects the durability and service life of the coatings and helps to optimize the Coating thickness. The standard emphasizes the scope and units of testing, as well as safety and environment considerations during implementation, providing a scientific basis for the performance evaluation of pipeline coatings.