This experiment was conducted to study the effects of different processing soybean meal and Lactobacillus acidophilus culture on growth performance and intestinal morphology of weaned piglets. A total of 240 weaned piglets with similar genetic background, parity and body weight at 21 days of age were randomly divided into 5 groups with 4 replicates in each group and 12 piglets in each replicate. Pigs in control group were fed a corn-soybean meal basal diet, the diet of fermented soybean meal group was used 10% fermented soybean meal replaced some common soybean meal, the diet of expanded soybean group was used expanded soybean replaced all common soybean meal, and the diets of Lactobacillus acidophilus culture groups were supplemented with 3% and 5% Lactobacillus acidophilus culture, respectively. The digestive energy and crude protein and other nutrient levels of the diet were similar in each group. The experiment lasted for 21 days. The results showed as follows:1) compared with the control group, the ratio of feed to gain of weaned piglets in fermented soybean meal group was significantly decreased (P<0.05), the average daily feed intake of weaned piglets in 3% Lactobacillus acidophilus culture group was significantly increased (P<0.05). The average daily feed intake of weaned piglets had no significant difference between 3% Lactobacillus acidophilus culture group and 5% Lactobacillus acidophilus culture group (P>0.05). 2) The villus height in duodenum, jejunum and ileum of weaned piglets in 3% and 5% Lactobacillus acidophilus culture groups was significantly higher than that in control group and fermented soybean meal group (P<0.05). The villus height to ctypt depth (V/C) value in duodenum, jejunum and ileum of weaned piglets in 3% and 5% Lactobacillus acidophilus culture groups was significantly higher than that in control group and fermented soybean meal group (P<0.05). The V/C value in duodenum of weaned piglets in expanded soybean group was significantly higher than that in control group (P<0.05). 3) Under the transmission electron microscopy, the jejunum microvillus was relatively thin and differs in length in the control group, but it was intensive and neat in 3% and 5% Lactobacillus acidophilus culture groups. In conclusion, diet added with fermented soybean meal or Lactobacillus acidophilus culture can promote the growth of weaned piglets, and diet added with Lactobacillus acidophilus culture can improve the intestinal morphology of weaned piglets. By considering the growth performance and intestinal morphology, the optimum addition level of Lactobacillus acidophilus culture in weaned piglets, diet is 0.3%.