The invention provides bacillus amyloliquefaciens EZ99. The bacillus amyloliquefaciens is gram positive bacteria, exists in plant rhizosphere soil, has no pathogenicity for people and plants, is collected from an orchard county, in the west of a Qilihe district in the Lanzhou city of the Gansu province, and has been identified, registered and preserved in the China common microorganism strain preservation center, and the preservation number is CGMCC No.13267. Component analysis is performed on bacterial colonies formed by the bacillus amyloliquefaciens on a PMA and MS culture medium, and it is found that the bacillus amyloliquefaciens has the characteristic of synthesizing and secreting exopolysaccharides. Optimal culture medium formulas and fermentation optimal conditions based on fermentation production of the exopolysaccharides of the strains are built, a fermentation solution is subjected to centrifuging, alcohol precipitation, dialysis and chromatographic separation, four purification polysaccharide components are obtained, and four-polysaccharide-component monosaccharide composition and monomer molecular weight are determined. The exopolysaccharides obtained through the strain and the method have the various applications of medicines, cosmetics, food additives, biological film raw materials and the like.