Environmental microbial DNA extraction is the foundation of microbial community research by molecular biology techniques, and its structural integrity and the purity of DNA extracted is directly related to the subsequent experiment results. DNA extraction method is not a unified standard because of various environmental samples, including water, soil and activated sludge, the traditional fermented food, liquor-making environment, etc. Now, there are many methods of DNA extraction, they can be divided into direct and indirect extraction ones. The direct extraction methods are simple, less time-consuming, while presenting impurities. However, complex indirect extraction operations are time-consuming, but the products are pure. Based on the comparison of the different DNA extraction methods, we focus on the research progress of DNA extractions of liquor brewing environment and the large fragments.