The invention discloses a method for constructing a suppression subtractive hybridization (SSH) library of oryza rufipogon threatened by bacterial blight germs. The method includes steps of: sample processing, total ribonucleic acid (RNA) extraction, mRNA purification, suppression subtractive hybridization and polymerase chain reaction (PCR) amplification of testing parts and driven elements, PCR products and polarization mode dispersion 18-T (pMD18-T) carrier connection restraining, connection product conversion, monoclonal storing and the like. The SSH library of oryza rufipogon threatened by bacterial blight germs constructed by the method is high in sensitivity, even length of insertion elements of the library is 450bp, a large number of difference expressed sequence tags (ESTs) of the oryza rufipogon threatened by the bacterial blight germs can be obtained fast in one step, partial sequence information is provided for separating overall-length cDNA sequence of clone bacterial blight resisting related genes, simultaneously important theoretical basis for improvement of biology is provided and new bacterial blight resisting related genes can be obtained.