The traditional smallpox vaccine vaccination method in our country is the skin scarification method. The operation process is: first drop 10μl of the vaccine (the dose is about 2×10 PFU) on the vaccination site, and then scratch, so that the vaccine enters through the damaged skin, but actually the amount of vaccine enters in the human body is far less than 10μl. At present, WHO recommends using bifurcated needle for immunization. Compared with the traditional methods, this method is simple and easy to use. Although dipping of vaccine by use the bifurcated needle is about 2.5μl, its immune effect is the same as the vaccination effect of 4 times the dose (10μl) of skin scratches, on the basis of ensuring the vaccination effect, the dasage of vaccine is reduced, and the absorption rate of vaccine is improved compared with the traditional method.