The invention relates to the technical field of 
animal disease detection, and discloses a preparation method of a detection 
reagent for 
porcine circovirus type 2. The preparation method specifically comprises the following steps of S1, expression of recombinant ORF2 
protein, wherein pET-28a-ORF2 is converted into 
escherichia coli BL21 competent cells, the positive 
escherichia coli BL21 competent cells are selected for clone and inoculated into an LB culture medium containing 
kanamycin, overnight culture is performed, 50 microliters of a 
bacteria solution is taken the next day to be inoculatedinto 5 milliliters of the LB culture medium containing the 
kanamycin, culture is performed for 2 h until the OD600 value is 0.6-0.8, IPTG with the final concentration of 1 
millimeter is added, sampling is carried out after induction is performed for 8 h, and a strain pET-28a-BL21 is induced as a 
negative control, and the 
protein expression situation is identified by SDS-PAGE 
gel electrophoresis; S2, soluble analysis of the recombinant ORF2 
protein, wherein 2 microliters of a recombined strain pET-28a-ORF2-BL21 is added into 2 milliliters of the LB culture medium containing the 
kanamycin. The preparation method of the detection 
reagent for the 
porcine circovirus type 2 can more effectively improve the production efficiency, and can also improve the accuracy of the detection 
reagent for detecting the 
circovirus type 2.