The invention provides a talaromyces flavus, and also relates to the application of the talaromyces flavus in the inhibition of a variety of plant pathogens. The preservation number of the talaromyces flavus qw12 is CGMCC5067, the talaromyces flavus colony is round, the texture is flocculent and fluffy or flocculent, and the front of the colony is yellow; the conidiophores have penicilli, and the spore is spherical; the primordium is nearly cylindrical, big and curved; the gymnothecium is spherical or nearly spherical, the ascus is spherical, and the ascospore is spherical or nearly sphericaland unicellular. The antagonistic bacterium provided by the invention can effectively inhibit the growth of valsa sordida, rhizoctonia solani, corn sheath blight fungi, curvularia lunata, colletotrichum gloeosporioides, fusarium graminearum, alternaria alternate, cryphonetria parasitica, colletotrichum nicotianae and other plant pathogens, effectively prevent plant diseases, reduce the dosage of chemical pesticide and the accumulation of the chemical pesticide in soil and help to increase the quality and yield of economic crops in China, and therefore economic and social benefits are remarkable.