In the field of hematological oncology diagnosis and treament, Non-Hodgkin Lymphoma (NHL), as the most common malignant tumor of the lymphatic system, accounts for 90% of all lymphomas. Its complex subtypes (over 100) and heterogeneity pose immense challenges to clinical treatment, Minimal Residual Disease (MRD) monitoring has become a core method for evaluating efficacy, predicting relapse risk, and guiding individualized treatment. Next-Generation Sequencing (NGS) deep sequencing technology based on circulating tumor DNA(ctDNA)-CAPP-Seq-has achieved a paradigm shift from "invasive"to "non-invasive" and from "local" to "systemic". Therefore, for MRD monitoring in NHL patients, especially in aggressive lymphomas or clinical scenarios requiring compreherisive molecular information support, the CAPP-Seq NGS testing solution based on ctDNA has become the most advantageous and promising choice.