The present invention provides a compound of a general formula I, a stereomeride, pharmaceutically acceptable salt or a solvate thereof, a preparation method thereof, and usages in preparing medicines for preventing and/or treating diseases or symptoms caused by drug-resistant tumors or drug-resistant bacteria and in preparing medicines for preventing and/or treating diseases or symptoms related to tumors, neurodegenerative diseases, allogeneic transplantation rejection, and infection. Preferably, the diseases or symptoms related to tumors, neurodegenerative diseases, allogeneic transplantation rejection, and infection are diseases or symptoms caused by a heat shock protein 70 (Hsp70). The compound in the present invention is used for overcoming a difficult problem of drug resistance of tumors, improves the effect of tumor treatment, and provides a new medical strategy for clinical tumor treatment.