Objective To explore the mechanism of liver injury induced by antituberculosis drug pyrazin⁃ amide（PZA）based on high mobility group protein 1（HMGB1）/extracellular vesicles（EVs）signal transducer and activator of transcription 3（STAT3）pathway. Methods 24 WT mice were randomly divided into two groups： WT+Con group and WT+PZA group；and 24 HMGB1⁃KO mice were randomly divided into two groups：HMGB1⁃ KO+Con group and HMGB1⁃KO+PZA group. Western blot was used to analyze the HMGB1 expression and the polarization of M1/M2 macrophages in mouse liver. In vitro，CCK⁃8 experiment was used to detect the effect of PZA（0，2，4，8，16，32 μmol/L）with gradient concentration on the activity of Huh7. The EVs released by Huh7 cells overexpressed by HMGB1 was isolated by ultracentrifugation，and its effect on the activation of THP⁃ 1 was analyzed. HMGB1 siRNAs was transfected into PZA⁃treated Huh7 cells，and EVs was isolated to detect the protein level of STAT3. Results Compared with 0 d，the level of HMGB1 in liver tissue of mice on 4 d，8 d，12 d and 16 d after PZA administration was significantly increased（P < 0.05）. Cell viability showed that PZA inhibited the proliferation of Huh7 cells，and the IC50 value was 5.62 ± 0.39 μmol/L. Compared with WT+Con group，in WT+ PZA group，significant progressive weight loss was observed（P < 0.001），and serum ALT and AST levels were significantly increased （P < 0.01）. Compared with WT+PZA group ，the weight of HMGB1⁃KO+PZA group increased significantly（P < 0.001），and the serum levels of ALT and AST decreased significantly（P < 0.05）. Compared with WT+PZA group，the expression of i⁃NOS in liver tissue of HMGB1⁃KO+PZA group decreased signif⁃icantly（P < 0.001），and the expression of CD206 increased significantly（P < 0.05）. Compared with EVs ⁃Vector group，the expression of iNOS in THP⁃ 1 cells in EVs⁃HMGB1 group increased significantly（P < 0.001）. Compared with Con+ si ⁃NC group，the level of STAT3 in EVs of Huh7 cells in PZA+ si ⁃NC group increased，while HMGB1 knockout could weaken the effect of PZA. Conclusion HMGB1 gene knockout in mice reverses PZA⁃induced liver injury and M1 macrophage activation. In addition，PZA⁃induced HMGB1 upregulation can promote the secre⁃ tion of STAT3⁃rich EVs by hepatocytes，and the EVs can promote the polarization of M1 macrophages.