3-Chloropropyltrimethoxysilane (CPTMS) was grafted on the surface of silica coated Fe3O4 core (Fe3O4@MCM-41) and then condensed with thiocarbohydrazide (TCH) to obtain Fe3O4@MCM-41-CPS-TCH. Then the heterogeneous Fe3O4@MCM-41-CPS-TCH-Pd nanocatalyst was synthesized by adding palladium(II) chloride to functionalized Fe3O4@MCM-41. The resultant nanomaterials were characterized using several techniques such as FT-IR, XRD, FE-SEM, HRTEM, EDS, BET, VSM, XPS, AAS and TGA. Then, the efficiency of this Palladium based magnetic nanocomposite was examined as catalyst for the preparation of biaryl derivatives using the Suzuki coupling of phenylboronic acid with various aryl halides in H2O/EtOH as a green solvent. The as-synthesized nanocomposite was also checked for the Heck–Mizoroki coupling reaction of various aryl halides and styrene. This catalytic system was easily retrieved by a magnetic field and reused for several times without distinct reduction in catalytic activity.