Abstract: The test method is culturing triadimefon in edible fungi base, spraying on fruiting body, mixing substrates with drug residues in Jilin Agricultural University for making safety standards of triadimefon residues, and the author detected residual dynamic of on edible fungi and substrates by gas chromatographymass spectrometry. The results showed that triadimefon in edible fungi and substrates of the degradation process were in line with a kinetic equation, half-life of triadimefon in edible fungi and were 2.3-3.1 d, and 14.2 d. Mushroom, citrinopileatus and substrates of triadimefon residues at harvest period were less than 0.01 mg/kg. The method was accurate and reliable, which provided scientific basis for our country in the MRL established on edible fungi.