Abstract: Due to the mild working condition and good selectivity as a catalyst,gold nanoparticles(AuNPs) have attracted increasing attention and were widely used in multi-phase green catalytic process.However,AuNPs in solution are unstable,susceptible to aggregation,and difficult in recovery which limits their applications.Inspired by the universal adhesive ability and redox activity of polydopamine(PDA),the catalytic particle(SiO₂@PDA@Au),composed of a silica core particle,a PDA interlayer coated on the core,and the in-situ reduced AuNPs deposited on the PDA layer,was designed and prepared.PDA can be coated on SiO₂ surface tightly and continuously,and the in-situ reduction and loading of AuNPs can be efficiently achieved.The amount of AuNPs increases upon increasing the thickness of PDA.The obtained AuNPs are around 30 nm in diameter with narrow size distribution and without aggregation.The SiO₂@PDA@Au hybrid catalysts with 1.59% of AuNPs loaded exhibit good catalytic performance(K_app=1.613 4 min^-1) with excellent recycling stability for the reduction reaction of methylene blue(MB).