The invention discloses a PCR detection and identification method capable of distinguishing pyricularia grise and magnaporthe oryzae and belongs to the technical field of plant fungus molecule biological detection. The PCR detection and identification method includes the steps of A, extracting DNA, to be specific, respectively extracting DNA of pyricularia grise and magnaporthe oryzae; B, designing primers, to be specific, designing a pair of specific primers Mol3-F/Mol3-F by inserting two ends of the retrotransposon of 849bp into a coding region of avirulence gene PWL3 of pyricularia grise; C, performing PCR, to be specific, performing PCR amplification by taking the extracted total DNA of pyricularia grise and magnaporthe oryzae as a template, so as to obtain an amplification product; D,determiningresults, to be specific, subjecting the amplification product to electrophoresis detection, if a target band of 1771bp is detected, then determining the product as pyricularia grise; if aband of 922bp is detected, then determining the product as magnaporthe oryzae. The PCR detection and identification method can rapidly accurately distinguish pyricularia grise and magnaporthe oryzae which are difficult to distinguish, and has a great significance in field spreading, breeding and evolving of Pyricularia on natural conditions.