The invention relates to Polysaccharide-coated GoldMag particles (DPGPs) and the method of its synthesis, which characterized GoldMag particles as a core and natural or synthetic biodegradable polysaccharide such as dextran, cyclodextrin and derivatives as shell. DPGPs are synthesized by mixing Polysaccharide-coated GoldMag particles (DPGPs) with drug through physical bond. The preparation of the drug-loaded composite particles include: preparing the polysaccharide-coated GoldMag particles and then loading the drug on the polysaccharide-coated GoldMag particles. The drug-loading process is carried out through directly mixing the polysaccharide-coated GoldMag particles with the drug solution by the shaker. That means the polysaccharide-coated GoldMag particles load the drug through affinity adsorption.