The invention discloses a bacillus licheniformis and application thereof to prevention and treatment on melon fusarium wilt. The strain is a bacillus licheniformis strain LT4-3, is obtained through being separated from river mud of a canal in Jining, Shandong province, is collected in CGMCC (China General Microbiological Culture Collection Center) on Sep 26th, 2017, and has the preservation numberof CGMCC No.14745. Experiment results show that the bacillus licheniformis strain LT4-3 wettable powder has the obvious effect on preventing and treating the melon fusarium wilt; the prevention and treatment effect reaches 74.31 percent; the growth condition of melons is good; no medicine hazards occur.