The ISO 29601 standard specifies a method for assessing the porosity of Dry-Film when corrosion protection is carried out through protective coatings systems. Porosity is an important factor affecting the corrosion protection performance of coatings, and higher porosity may lead to a decrease in the protection performance of coatings. The standard provides a method for evaluating the porosity in Dry-Film, which is designed to help ensure the sealing and protection performance of coatings and ensure the effective protection of metal substrates by coatings. The implementation of this standard can effectively detect possible defects in coatings during application, and provide a scientific basis for the quality control of anti-corrosion coatings and the optimization of coating process.