The invention relates to a detection method and application of a rice blast resistance gene Pigm, belongs to the technical field of agricultural biology and particularly relates to a specific molecular marker for High-Resolution Melting Curve Analysis (HRM) of the rice blast resistance gene Pigm and a method for detecting the rice blast resistance gene Pigm by virtue of a primer. According to the detection method, a rice 60K gene chip is utilized for carrying out whole-genome scanning on Gumei #4, and wuyunjing #7 and 9311, an HRM primer is designed by virtue of different variation sites, on which Gumei #4 are different from wuyunjing #7 and 9311, close to two ends of the gene Pigm, a molecular marker completely co-separated from Gumei is developed at each of two ends, and a middle-high-flux assistant selection system is established, so that the disease-resistant breeding efficiency of rice can be greatly improved.