The invention discloses a method for extracting an anti-bacteria active component from Japanese retinispora, which relates to a method for extracting an active component. The method solves the problemthat the exiting method for extracting the anti-bacteria active component from Japanese retinispora has low anti-bacteria substance content in the extractive and is not applicable to industrialized production. The method comprises the steps: firstly, a Japanese retinispora material is ground, goes through a sieve, is wrapped with filter paper after air drying, put into a Soxhlet extractor and then into a thermostatic waterbath for conducting continuous refluxing extraction with an n-hexane extraction solvent, thus obtaining an extractum extractive after a rotating thin film evaporator evaporates off the n-hexane extraction solvent; and secondly, a wet method is used for filling a chromatographic column and then the extractum extractive is separated, thus obtaining the anti-bacteria activecomponent in Japanese retinispora. The method has low requirement on equipment condition, easy implementation, concise steps, short production period and low production cost, and is suitable for industrialized production; the production schedule can be flexibly arranged; and the extractive content reaches 73.15 percent, thus leading to anti-bacteria effect.