The present invention belongs to a real-time detection method of the frequency of 
drug resistance genes in 
Sclerotinia sclerotiorum syngen, which can be used for 
drug resistance monitoring and popularity warning of 
carbendazim and other 
benzimidazole fungicide resistance in 
sclerotinia sclerotium disease of cole and the like crops. The detection method is divided into three major steps, the first step: respectively extracting the nuclear 
genome DNA of known 
drug-resistant strains, sensitive strains and sample to be measured; the second step: using the 
specific detection primers of drug-resistant strains and 
Sclerotinia sclerotiorum strains for real-time quantitative PCR reactions, respectively establishing the standard curves of the drug-resistant strains and 
Sclerotinia sclerotiorum strains detection; the third step: sample to be measured respectively using the two 
specific primers for real-time quantitative PCR reactions, contradistinguishing with the established standard curves, obtaining the corresponding numbers of the drug-resistant strains and sensitive strains and the proportion of the drug-resistant strains in the total number of the 
Sclerotinia sclerotiorum. The use of real-time quantitative PCR technology can perform high-
throughput, rapid and accurate quantitative detection of the number of field drug-resistant 
Sclerotinia sclerotiorum and its proportion in the 
pathogen syngens, which has high-
throughput characteristic. Compared with the conventional 
biometrics and general PCR detection of drug-resistant strains, the invention is time-saving, cost-saving and fast. The whole process from directly extracting the 
genome DNA from the sclerotia, 
disease spots and spores collected to real-time quantitative-PCR detection is only 6h needed, and the detection accuracy rate is more than 96%.