This standard specifies a method for the determination of the content of magnetic substances in nano-cathode materials for lithium batteries using Inductance Coupled Plasma Emission Light Spectrometry (ICP-OES). It includes the principle of the test, environmental conditions, reagents and instruments, test procedures and analysis of results. It is suitable for the determination of magnetic substances such as iron, cobalt, chromium, nickel and zinc in the content between 0.02 × 10 ^ -6 and 20 × 10 ^ -6. This standard provides a reliable method for evaluating the content of magnetic substances in nano-cathode materials, ensuring the Stability and safety of battery performance.