The invention discloses an attenuated vaccine of contagious ecthyma virocyte as well as a preparation method and an application thereof. In the attenuated vaccine of the contagious ecthyma virocyte disclosed by the invention, the effective component is the attenuated vaccine caused by passage of the contagious ecthyma virocyte which is obtained by automatic separation and passage-attenuated cultivation of the inventor, and the preservation number is CCTCC NO:V201406. The attacking protection test result shows that the prepared orf virus (ORFV) cell attenuated vaccine is safe, and can generate effective immune protection force. Therefore, the attenuated vaccine has important practical significance on development of the safe and efficient attenuated vaccine and large-scale production of the attenuated vaccine of the contagious ecthyma virocyte by using the disclosed attenuated strain to prevent and control contagious ecthyma.