Abstract: To address the impact of electromagnetic radiation and interference on the operation of electronic equipment to a certain extent and potential harm to human health, M-type strontium ferrite (SrFe₁₂O₁₉) nanosheets were prepared by the hydrothermal method. Subsequently, Ag₃PO₄ nanoparticles with different contents were attached to the surface of SrFe₁₂O₁₉ by iron exchange method to prepare SrFe₁₂O₁₉/Ag₃PO₄ series nanocomposite samples. The structural and morphologies were characterized and analyzed by X ray diffraction (XRD) and scanning electron microscope (SEM). Magnetic properties and microwave absorption properties were measured and analyzed by vibrating sample magnetometer (VSM) and vector network analyzer (VNA), and the effect of different amounts of silver phosphate attachment on the microwave absorption properties of the nanocomposites was explored.The results indicate that Ag₃PO₄ nanoparticles adhere to the surface of the hexagonal strontium ferrite sheets, as the content of Ag₃PO₄ increases, the amount of Ag₃PO₄ attached to the surface of SrFe₁₂O₁₉ also increases. For the mass fraction of 3% Ag₃PO₄, the minimum reflection loss of SrFe₁₂O₁₉/Ag₃PO₄ composites reaches −23.6 dB with a matching thickness of 5.0 mm. The reflection loss less than −5.0 dB is obtained in 4.0 GHz(3.9−7.9 GHz) for an absorber thickness of 5.5 mm, indicating that SrFe₁₂O₁₉/Ag₃PO₄ nanocomposites have good application prospects in the field of microwave absorption.