The invention discloses bacillus capable of producing a cytotoxic active matter and a method for preparing the cytotoxic active matter by virtue of the bacillus. With the application of the preparation method provided by the invention, on the basis of full use of a green biomass resource, and by adopting easily available raw materials, simple strain fermentation culture conditions as well as an easily controllable compound preparation process, the active matter can be produced at a relatively high yield. Researches on the cytotoxic active matter, which is separated from a bacillus HZ16 fermentation extract, can promote the development of drugs, and in particular drugs having antineoplastic activity; and the rapid detection of cytotoxic activity can offer a solution for high throughput screening of novel drugs; therefore, the method is applicable to research and development of novel antibacterial and antineoplastic drugs and the like in the medicine field.