An orange-like catalyst of Pd nanoparticles supported by magnetic Fe3O4/polypyrrole nanocomposite is facilely prepared. It shows great activity for Suzuki coupling reactions in neat water under atmospheric pressure. This magnetic and water-soluble catalyst avoids the use of toxic solvents in traditional process of coupling reactions and can be easily recovered by mean of a convenient magnetic separation technique, demonstrating in both environmental friendliness and recyclability.