Provided is a piperazinotrizole compound represented by general formula I or an isomer, a pharmaceutically acceptable salt, ester, prodrug or hydrate thereof. Also provided are a method for preparing the compound, a drug composition containing the compound, and a use thereof as a high-selectivity poly(ADP-ribose) polymerase-1 (PARP1) inhibitor in the preparation of drugs for the prevention and/or treatment of PARP-related diseases.