Locoweed is a poisonous plant wildly distributed in most areas of the world,which causes livestock poisoning or death with serious economic loss.The Astragalus strictus belongs to a species of Iocoweed.It is mainly distributed in Tibet of China and is a serious hazard to the local livestock industry.The objective of this study is extracting and purifying condition of Swainsonine from Astragalus strictus with the cellulase extraction method.An optimum extracting technology of SW from Astragalus strictus was investigated through the orthogonal experiment under the cellulose assistance conditions,and then the content of swainsonine was analyzed with gas chromatography (GC) method.The optimized extraction conditions were as follow:The crushed mesh is 40; solid-liquid ratio is 1∶40 (g/ml); enzyme dosage is 3.5%; enzymatic time is 3 h.Under the above conditions,the extraction percentage of the swainsonine was 0.003 941%.The conditions for extracting swainsonine with cellulase extraction method are mild,it is easy to utilize industrial production.It is benefit for producing swainsonine from Astragalus strictus.