A method of extracting target nucleic acid and performing PCR augmentation comprises the following steps: adding a cracking liquid, a sample containing target nucleic acid and a reaction liquid which performs PCR augmentation into a PCR reaction tube and evenly mixing; placing in the PCR apparatus for performing PCR augmentation. The invention only needs simple instrument to rapidly and high efficiently extract target nucleic acid from the sample and to synchronously perform real-time fluorescence PCR augmentation detection; the invention has wide detection linear range, accurate quantification for samples of different concentrations, good specificity and good repetitiveness; the invention is extremely simple in operation and suitable for the PCR apparatus of different types; it can be widely applied to the fields of detection of pathogenic microorganism, medicolegal expertise, tissue and blood typing, genetic mutation detection.