The invention relates to a SYBR green I fluorogenic quantitative PCR (polymerase chain reaction) detecting method of pig proliferative enteropathy Lawsonia Intracellularis. The method provided by the invention comprises the following steps of: extracting pig Lawsonia Intracellularis DNA, designing primers, carrying out PCR amplification on aspa gene segments of PPE (polyphenylene oxide polyphenyl ether), cloning and identifying aspa genes of pig proliferative enteropathy, preparing a standard plasma template, amplifying fluorogenic quantitative PCR so as to obtain an amplification kinetic curve and a standard curve, testing the specificity, the sensitivity, the repeatability and stability, and detecting clinical disease material samples. The method provided by the invention has favorable specificity, sensitivity, repeatability and stability, and can identify and diagnose clinical suspected PPE infected or morbidity pigs simply, conveniently, rapidly, specifically, sensitively and accurately, and can detect and monitor the infection in the early stage.