The present study, La0.7Sr0.3MO3 (M = Mn-, Co-, and Fe-) perovskite, has successfully been synthesized via two techniques; co-precipitation, and sol-gel auto-combustion. XRD, SEM, and EDX characterized the prepared samples. XRD and SEM showed that the as-prepared La0.7Sr0.3MnO3 and La0.7Sr0.3CoO3 have multiphase. La0.7Sr0.3FeO3, in comparison, is nanosized, has a single-phase perovskite, and has a rather homogenous particle size distribution. Additionally, EDX mapping analysis shows that all pieces are distributed uniformly. All calcined powders contain 100% LSF, more than 15% perovskite phase of LSC, 47% LSM, and other secondary phases such cobalt oxide, according to X-ray diffractometer results. At room temperature and magnetic field ± 20 kG. La0.7Sr0.3MnO3 exhibited weak ferromagnetic behaviour in a low magnetic field, whereas diamagnetic behaviour was seen in a high magnetic field. La0.7Sr0.3FeO3 samples behave as strong ferromagnetic. On the contrary, the photodegradation of La0.7Sr0.3MnO3 is 99% compared to 75% and 91% for other samples under UVA lights. The degradation rate for La0.7Sr0.3MnO3 is 0.179 higher, about 3.25 and 2.23, than the other samples. A La0.7Sr0.3MnO3 nanocomposite perform as a photocatalyst to enhance the efficiency of Methylene blue photodegradation.. This study boosts good UVA- photocatalysts with high efficiency for different kinds of dyes. Hence the catalyst possessed high stability and effieiency for continuous treatment of wastewater.