The paper studied that the separation, purification, identification of ricinine and allergen in Castor bean meal (CBM), the measurement method of ricinine content in CBM, the separation, culture and primary identification of microorganism, detoxification of CBM by microorganism, the degradation pathway of ricinine, effect of feeding detoxified and undetoxified CBM on sheep. The results of the study suggested that:Ricinine and allergen were separated and purified from CBM respectively, and were identified to be standard. The method of HPLC of ricinine content in CBM was founded.One strain of Lactobacillus and One strain of Actinomyceto were primarily identified to be Leuconostoc, Streptomyces respectively from plant and silage.The degree of detoxification rate of Lactobacillus, Actinomyceto, Fungi, yeast on CBM were different. The detoxification rate of yeast on CBM was higher significantly than that of Lactobacillus, Actinomyceto, Fungi on CBM (P<0.01). Among the treatment of yeast detoxified CBM, the addition of 5% wheat bran which was incubated by yeast to CBM after fermenting 3 days, the detoxification rate of ricinine was 93.05%, the allergen content of CBM was no more than 0.01%. And CP and Total amino acid content in detoxified CBM was not changed with respect to undetoxified CBM (P>0.05). In detoxified CBM, activities of acid protease, xylanase, β-1,4 glucanase were 1621.88 U, 1472.89 U, and 799.38 U respectively.Ricinine may be degradated to 3-carboxyl-4-methoxyl-l -methyl- 2-pyridone by ricinine nitrilase.Addition 10%, 20%, 30% detoxified CBM to concentrated feed of sheep after feeding sheep 40 days, sheep were healthy. Rumen fermentation of sheep which were fed detoxified CBM were not effected by detoxified CBM. Serum total protein, albumin (ALB), glutamate pyruvate transaminase (GPT) content of sheep which were fed detoxified CBM were normal.Ricinine content was 0.0003% in liver of sheep which was fed 30% undetoxified CBM in concentrated feed after feeding 40 days. At the same time, serum ALB and GPT content of sheep at the end of the experiment were 23.38%, 62.63% (P<0.01) respectively more than those of sheep at the beginning of the experiment.