The invention relates to a primer combination capable of detecting three kinds of 
streptococcus simultaneously. The primer combination consists of upstream and downstream primers capable of detectingstreptococcus agalactiae, as shown in SEQ ID MO:1, 2, upstream and downstream primers capable of detecting 
streptococcus dysgalactiae, as shown in SEQ ID MO:3, 4, and upstsream and downstream primerscapable of detecting 
streptococcus iniae, as shown in SEQ ID MO:5, 6. A 
reagent kit consists of 
a DNA extraction 
reagent and a PCR reaction 
reagent, wherein the 
DNA extraction reagent consists of a TEbuffer solution, 
proteinase k, 
chloroform, 
isopropyl alcohol, 
ethanol and redistilled water, and the PCR reaction reagent contains a reaction 
buffer solution, dNTPs, 
DNA polymerase, the 6 primers anddeionized water. A method for detecting the three kinds of streptococcus simultaneously comprises the steps of extracting 
DNA in samples through the extraction reagent, performing PCR amplification on the DNA through the reaction reagent, and performing 
gel electrophoresis on amplification products. The three kinds of streptococcus can be detected simultaneously, detection is simple, quick, highin sensitivity and high in specificity, and the primer combination and the method can meet requirements for large-scale 
molecular epidemiology investigation and analysis of aquatic animals and qualitysafety detection of aquatic products.