The invention discloses a preparation method and application of a vaccine of porcine circovirus type 2 virus-like particles. The preparation method provided by the invention comprises the following steps of: cloning an artificially optimized gene coded with porcine circovirus type 2 Cap protein in a baculovirus vector, transfecting an insect cell sf9 to obtain recombinant baculovirus, and strongly expressing the Cap protein in the cell by infecting high five cells through the recombinant baculovirus. The invention further discloses a method for purifying the virus-like particles rapidly, simply and conveniently. The purifying method provided by the invention comprises the following steps of: centrifugally collecting the high five cells to pre-cool PBS (Phosphate Buffered Saline) re-suspension cells by ice, and cracking a cell suspension cracking solution into clarified liquid by using a cell homogeneous instrument. The virus-like particles are purified through a gel filtrating chromatography method. By using the method provided by the invention, the complex cell cracking solution can be rapidly purified into specific virus-like particle protein, and the purity is above 90%.