Abstract: Taking Phellinus igniarius strain as the test material, the space mutagenesis method was used, 109 mutant strains were obtained through multi generation isolation and purification.After numbering and culturing the mutant strains, 47 mutant strains of Phellinus igniarius were initially screened out through macroscopic colony observation, microscopic hyphal comparison and antagonistic test.The growth rate of the mutant strains and the parent strain H0 was compared.It was found that the speed of 9 mutant strains was significantly higher than that of the starting strains.The mycelial biomass was compared by liquid fermentation culture method, and the flavonoid yield of mutant strains was compared after optimizing the extraction process of flavones from liquid fermentation mycelia of Phellinus igniarius,in order to provide reference for space mutation breeding of Phellinus igniarius.The results showed that the mutant strain H68 had the characteristics of rapid growth, good growth, and significantly higher mycelial flavone production than the starting strains.After identification, H68 belonged to the genus Phellinus,GenBank accession number MN153566.1,homology 99.85%,and it was determined to be the space mutant strain of the starting strain H0.