The invention discloses a preparation method and product of a swine fever live vaccine. The preparation method comprises the following steps: (1) culturing a swine-derived 
continuous cell line; (2) inoculating the swine-derived 
continuous cell line into a seed 
virus for producing the swine fever live vaccine, thereby obtaining a swine fever weak-
virus vaccine strain; (3) carrying out 
virus multiplication on the swine fever weak-
virus vaccine strain; (4) determining the virus value of the multiplied 
virus suspension by an 
immunofluorescence method; and (5) adding a freeze-
drying protective agent and 
antibiotics into the qualified 
virus suspension to carry out vaccine preparation and freeze-
drying. Since the swine fever live vaccine is prepared from the 
cell line, the difference of quality among different batches is small, and the invention has the characteristics of simple and stable technique, high yield, low cost and the like, is easy to operate, and has feasibility and amplification of industrialized 
mass production. In addition, the 
immunofluorescence method, which has the advantages of high detection sensitivity, high speed, high specificity, high accuracy, high repetitiveness and reliable result, is used for determining the virus value of the multiplied 
virus suspension. The swine fever live vaccine disclosed by the invention can 100% protect the 
attack of swine fever strong virus.