The invention relates to application of ferulic acid and oligosaccharide preparation by producing enzymes from Salicornia bigelovii straws fermented by microorganism. The microorganism in the invention refers to Aureobasidium pullulans; the Salicornia bigelovii straws are dried and crushed to a certain particle diameter, and then a mixed enzyme preparation of xylanase and ferulic acid esterase is generated after the metabolism of the Aureobasidium pullulans; the cell walls of the Salicornia bigelovii straws are degraded under the synergistic effect of the mixed enzyme so as to obtain physiologically active substances, such as the ferulic acid and oligosaccharide. The invention has the effects of oxidation resistance, free radical elimination, thrombus resistance, blood fat reduction, coronary heart disease prevention and cure, bacteria resistance, inflammation elimination, mutation resistance and cancer prevention, can be widely applied in industries of medication, food and cosmetics, and can prominently increase the economic value of the straws, i.e., by-products of Salicornia bigelovii.