Immune system diseases, malignant tumors, and traumatic injuries can directly damage the structure and function of lymphoid organs, while subsequent radiotherapy, chemotherapy, and lymph node dissection further damage the patient's immune system, leading to immune dysfunction, metabolic disorders, and increased susceptibility to infection, which seriously affect the patient's prognosis and quality of life. In this context, nanotechnology plays a key role in lymphoid organ regeneration and immune function recovery, including improving the therapeutic effect through targeted drug delivery systems, using targeted imaging probes to achieve tumor prediction and early detection, combining nanoplatforms with immunotherapy and photodynamic therapy to achieve synergistic therapeutic effects, and using nanomaterials to regulate the tumor microenvironment to enhance the sensitivity of traditional treatments. In addition, biophysical simulation strategies that simulate the microenvironment of lymphoid organs have also attracted widespread attention, aiming to construct a native cell environment to support the regeneration and functional recovery of damaged lymphoid tissues, or to simulate immune cells to regulate lymphocytes and induce specific immune responses. The multifaceted application of nanotechnology provides promising prospects for lymphoid organ regeneration and immune system repair.