A novel magnetic Fe 3 O 4 /SiO 2 /P(GMA-co-EGDMA) composite nanoparticles grafted with hyperbranched/linear polyethylenimine ligand was fabricated. Subsequently, Nano palladium was effectively anchored on this carrier through the complexation between Pd 2+ ions and multifunctional organic ligands, then a novel supported Pd nanoparticles catalyst with good dispersion and high loading of Pd nanoparticles was successfully prepared after the follow reduction process. Afterwards, the as-prepared supported Pd nanoparticles catalyst was characterized by SEM, TEM, XRD, FITR, TG, ICP-AES, respectively.Ultimately, the catalytic performance of the supported Pd nanoparticles catalyst was investigated by catalysing the Sonogashira Cross-Coupling Reaction between aryl halides and arylacetylene. Research shows that the novel supported Pd nanoparticles catalyst exhibits very superior catalytic activity in catalysing Sonogashira cross-coupling reaction between aryl halides and arylacetylene even at the absence of the cocatalyst (CuI), and the side reaction to produce by-product (1,3-diyne) can be inhibited effectively. In addition, this supported Pd nanoparticles catalyst exhibites stable recovery and high catalytic activity for it can be effectively reused 8 times without obvious loss of catalytic activity. Especially, the yields of the target products of the Sonogashira cross-coupling reaction between iodobenzene and phenylacetylene, 3-aminophenylacetylene and 4-(ethynyl)phthalic anhydride can reach up to about 79%, 78% and 95% after this novel supported Pd nanoparticles catalyst being used eight times, respectively.