The invention provides a novel method for extracting phage genome DNA. The novel method comprises the following steps: after amplifying phage lysate, removing cell debris and nucleic acid substances of host bacteria, adding PEG6000 to settle phage, after resuspending by TM buffer liquid, avoiding chloroform extraction, directly adding nuclease, removing the genome of the remaining host bacteria, then replacing protease K by using urea, after degeneration of coat protein, separating the protein from the genome DNA by agarose gel electrophoresis, and then recycling the genome DNA of the phage byusing a freeze thawing and recycling method. The method is simple and convenient to operate, is particularly suitable for phage sensitive to chloroform, and is wide in application range, experiment costs are greatly reduced, and extracting time is shortened.