The standard "GB/T 37158-2018 Nondestructive Testing, Test Method for Maximum Detectable Steel Film Thickness Detection by Industrial Computer Tomography (CT) " specifies the method for testing the maximum detectable steel Film thickness using industrial CT equipment. The standard is applicable to CT systems with radiation energies of 225 keV and above for the determination of their maximum detectable steel Film thickness when they reach specified spatial resolution under specific scanning and reconstruction conditions. The standard covers the terms and definitions required during the testing process and refers to relevant nondestructive testing terms and performance detection methods to ensure the accuracy and conformity of the test results.