TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preparation (Claimed): The method for preparing above-cited strain by (a) screening fermentation cottonseed meal culture by processing cottonseed meal from soil under tree and pond water, and diluting molded cottonseed meal in different gradients, coating the molded cotton to 0.1% of gossypol acetate Zhanjiang (Zha) culture medium flat plate, and stewing and culturing for 3-5 days at constant temperature of 30 degrees C, selecting different types of colony with excellent growth vigor, and further naturalizing and culturing the colony in 0.2-0.3% of gossypol acetate Zha culture medium to obtain strain resisting rather the high content of gossypol, (b) inoculating the test seed in slope storage culture containing 20 ml of potato liquid culture medium, and culturing in 100 ml of triangular flask at 30 degrees C and 200 revolutions/minute for 48 hours to obtain primary culture, using the obtained primary culture and inoculating culture to 1 ml of triangular flask in 250 ml filled with 100 ml of potato liquid culture medium, and obtaining secondary culture by culturing at 30 degrees C and 200 revolutions/minute and 48 hours, (c) evaluating mono-fungal fermenting effect by preparing the strain obtained through screening and purifying the liquid culture, and inoculating the strain to cottonseed meal fermentation substrate (100 g) with inoculum size of 5%, and culturing the strain for 48 hours at 30 degrees C, analyzing the fermenting effect, and performing culture verification of dominating strain, where the cottonseed meal fermentation substrate prepared by mixing cottonseed meal after crushing and screening the corn and wheat bran evenly in ratio of 7:2:1 to form basic substrate, mixing the water and substrate in ratio of 1:0.8, and sterilizing the obtained substrate for 30 minutes at 121 degrees C, and (d) evaluating strain combined fermenting effect by preparing the strain by screening liquid culture, inoculating the strain cottonseed meal substrate (100 g), where the inoculating ratio is 1:1:1 with inoculum size of 5%, placing the liquid culture in 500 ml of triangular flask, and stewing and culturing for 48 hours at constant temperature of 30 degrees C, and drying the obtained strain and detecting the content of free FG and CP, and analyzing fermenting effect.