The present invention relates to a novel microorganism Bacillus amyloliquefaciens KTGB0202 and a method for controlling plant pathogens using the same. More particularly, the present invention relates to a novel microorganism Bacillus amyloliquefaciens KTGB0202 (accession number: KCTC 10564BP) bacterium which has an excellent control effect against crop powdery mildew and a broad spectrum of antifungal activity against plant pathogenic fungi and inhibits tobacco mosaic virus infection, as well as an eco-friendly bacterial culture broth for controlling powdery mildew, which contains the same. Also, the present invention relates to antifungal substance KTGB0202AFO1 obtained by extraction and purification from the Bacillus amyloliquefaciens KTGB0202 bacteria. The inventive Bacillus amyloliquefaciens KTGB0202 bacteria have a broad spectrum of antifungal activity, and are excellent in activity continuance and used for controlling various plant pathogens, including powdery mildew.