The invention relates to the field of the preparation of biological polysaccharide, in particular to an improved method for extracting biological extracellular polysaccharide. The fermentation broth of the biological extracellular polysaccharide is subjected to the treatment of temperature rise, salting and alkali regulation in the method. Accordingly, the method can reduce the consumption of alcohol, increase the extraction yield of the biological extracellular polysaccharide and reduce the cost for extraction under the condition that the quality of the obtained biological extracellular polysaccharide is guaranteed. Therefore, the method is suitable for industrialized mass-production.