Tilapia mossambica streptococcus agalactiae oral attenuated freeze-dried vaccine

The invention discloses a tilapia mossambica streptococcus agalactiae oral attenuated freeze-dried vaccine and its preparation method. According to the invention, tilapia mossambica streptococcus agalactiae attenuated bacterial strain YM001 is performed with steps of enlarge cultivation, thalline collection and freeze-drying preparation to obtain the oral attenuated vaccine. The immunizing dose, immunization program and a vaccine usage method of the vaccine can be determined through tests. The immune efficacy, security and maneuverability of the vaccine can be detected and confirmed through field tests, the result shows that the vaccine has the advantages of high protection effectiveness, good security, convenient usage and low cost, the vaccine can be used for preventing tilapia mossambica streptococcus agalactiae, and has high business value.