Protective antigen composition capable of excitating organism to generate immunity against plague and use thereof

The invention discloses a protective antigen composition which can motivate an organism to generate immunity to plague, and the application thereof in preparing a plague vaccine. The protective antigen composition is a composition which is mixed by a natural F1 antigen and an rV270 antigen according to the weight ration of 1-2 to 2-1. The immune protection effect of the composition is evaluated by animal experiments and the evaluation result shows that the protective antigen composition that is composed of the natural F1 antigen and the rV270 antigen performs good immune protection effect to the infection caused to mice, guinea pigs and rabbits by plague bacillus, has relatively high safety and can be used for preparing a subunit plague vaccine.