Investigations　on　the　microcrack　distribution　characteristics　and　bioleaching　behaviors　of　particles　were　conducted　to　obtain　better　bioleaching　efficiency　and　deepen　the　mechanism　understanding.　Results　indicate　that　comminution　by　high-pressure　grinding　roll　(HPGR)　is　the　desirable　method　for　obtaining　particles　with　more　abundant　and　wider　microcracks.　Fixing　the　HPGR　pressure　at　4　MPa　results　in　the　highest　bioleaching　efficiency　for　copper　extraction,　namely　86%　for　the　shaking　flask　bioleaching　(particle　size:　＜1.7　mm)　and　52%　for　the　column　bioleaching　of　particles　(particle　size:　3.35–6.7　mm).　The　suggested　model　for　reaction　kinetics　of　microcrack-containing　particles　implies　that　more　abundant　and　wider　microcracks　can　promote　the　exposure　of　both　Cu-containing　phases　and　ferrous　iron　as　well　as　solution　infiltration,　as　evidenced　by　the　COMSOL　simulation　results　and　bacteria　proliferation　analysis.　The　results　highlight　the　importance　of　microcracks　for　enhancing　the　bioleaching　process　and　provide　insights　for　the　mechanism　understanding.　©　2023