In this work, the investigation of wave absorption, phase formation, crystal structure and magnetic properties of SrFe12O19 hexa-ferrites nanoparticles that synthesized by co-precipitation using a microwave heating system and polyaniline-SrFe12O19 was carried out by using a combination of vector network analyser (VNA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. Alternating gradient force magnetometer proofs the magnetic property of the hexa-ferrite nanostructures. We studied Sr Hexa-ferrite nanoparticles and nanocomposite by changing in many parameters like power of microwave system and calcination temperature. In this work, the investigation of wave absorption, phase formation, crystal structure and magnetic properties of SrFe12O19 hexa-ferrites nanoparticles that synthesized by co-precipitation using a microwave heating system and polyaniline-SrFe12O19 was carried out by using a combination of vector network analyser (VNA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. Alternating gradient force magnetometer proofs the magnetic property of the hexa-ferrite nanostructures. We studied Sr Hexa-ferrite nanoparticles and nanocomposite by changing in many parameters like power of microwave system and calcination temperature.