Abstract: Taking large-scale pig farming in China as the research object, the production efficiency of large, medium and small scale pig farming and the degree of pig industry agglomeration in 24 provinces（autonomous regions and municipalities）of China were measured, and the relationship between industrial agglomeration and production efficiency of pig farming was investigated by panel Tobit model. The results showed that the production efficiency of large-scale pig breeding decreased year by year from 2005 to 2018, while the production efficiency of small and medium-sized pig breeding increased slowly. The degree of industrial agglomeration in southern China is generally higher than that in northern China. The relationship between industrial agglomeration and technical efficiency of small and medium-sized pig breeding is “inverted U shape” , but it is negatively correlated with production efficiency of large-scale pig breeding. It is suggested to reduce the proportion of large-scale pig breeding in industrial agglomeration, promote moderate concentration of small and medium-sized pig breeding, guide the southern pig breeding industry to move to the north, strengthen the feed industry foundation, and vigorously develop breeding pig industry to improve the production efficiency of pig breeding.