Abstract: Treatment and utilization of animal manure water have become a big challenge for the healthy development of the breeding industry, as the impact of upcoming technology on large-scale livestock and poultry farming. Since slurries are an important source of ammonia emissions to the atmosphere, the representative methods to reduce ammonia emission include surface covering, and acidification technology. Surface covering technology refers to cover the surface of animal manure water, in order to reduce the gas exchange between animal manure water and air surroundings. However, this technology has only a few applications due to confined covering materials. In acidification technology, the acidifiers are added to the animal manure water, in order to reduce the loss of nitrogen during storage. This acidification technology has been widely used in Denmark and other countries in Europe. However, there is still a large gap in the field of fecal water acidification in China. Since only two institutions have studied the acidification technology of fecal water from the perspective of odor and greenhouse gas emissions, there is still lacking a large number of research data for the industrial utilization of fecal water acidification. In this study, sulphuric acid and alum were selected as acidifiers to treat cow slurry before and after solid-liquid separation. After adding sulphuric acid and alum, the pH value of the cow dung water and cow slurry can reach 6.0, under the blank control at the same time. The mechanism of n-form transformation was proposed for the process of acidification and storage of cow dung water and cow slurry by analyzing the indexes of ammonia mission, n-transformation and harmless effect. The results show that the addition of acidifiers can reduce the total loss of nitrogen by 6.3%-11.1%, and the emission of ammonia in the initial stage of cow dung water and cow slurry storage decreased, compared with those in the conventional techniques. Adding acidifier in the cow slurry can indirectly increase the concentration of dissolved oxygen, while reduce the pH value of the cow slurry during storage process, indicating the effective inhibition to the activity of fecal coliform in the cow manure water for easily harmless treatment. The addition of acidifiers can also inhibit the transformation of organic nitrogen to inorganic nitrogen under the action of microorganisms in the cow dung water and slurry, and thereby to improve the content of organic nitrogen during slurry storage, as well reduce the production of ammonium nitrogen, indicating that the acidifiers and ammonium nitrogen can generate ammonium salt with stable chemical properties. This finding can provide the technical translation of the acidification technology into industrial application in animal manure water during slurry storage.