Small nitrogen fertilizer enterprises had obvious advantages of the higher level of gas content and lower consumption.Compared to the middle nitrogen fertilizer enterprises,the small nitrogen ones formed a rational system in terms of craft and equipment,and the formation of gas system had a special history and background. In the process of learning technical transformation and innovation from small nitrogen enterprises, the middle nitrogen enterprises should analyze the small nitrogen industry’s experience of gas making as a system. In the way of technical transformation and innovation,the middle nitrogen enterprises should focus on the following aspects, improving the ability of breaking grate slag and adjusting time allocation, lowering the upper temperature and raising the lower temperature,increasing the height of the gas furnace and the carbon layer, and improving the process of craft.