One　of　the　most　important　wastewater　treatment　processes　is　microelectrolysis,　which　is　extensively　used　in　the　primary　treatment　of　pharmaceutical　wastewater.　In　this　study,　microelectrolysis,　as　a　pretreatment　method　for　the　refractory　metronidazole　pharmaceutical　wastewater　(MPW)　of　choice,　was　improved　using　the　Fenton　process　and　used　to　remove　the　chemical　oxygen　demand　(COD)　and　improve　the　biochemical　capability　of　MPW.　The　results　showed　that　the　highest　COD　removal　of　40.8%　was　obtained　in　the　presence　of　optimized　significant　factors　and　the　BI　(BI　=　biochemical　oxygen　demand　over　five　days/COD)　of　MPW　increased　from　0.10　to　0.31.　In　addition,　the　ultraviolet-visible　(UV-Vis)　spectroscopy　demonstrated　that　metronidazole　in　MPW　was　effectively　removed　during　the　combined　processes.　All　these　results　showed　that　microelectrolysis　combined　with　Fenton　oxidation　for　MPW　was　an　effective　treatment　process　to　achieve　higher　COD　removal　and　biodegradability　improvement.　Finally,　the　breakthrough　curves　at　different　flow　rates　were　measured　to　prove　the　feasibility　of　the　combined　process　under　optimal　conditions.