Bladder　dysfunction　seriously　affects　people＇s　quality　of　life.　The　accumulation　of　urine　volume　in　the　bladder　changes　the　bladder　volume,　which　changes　the　impedance　of　the　hypogastrium.　This　paper　constructs　a　finite　element　model　of　the　hypogastrium　and　bladder,　and　the　impedance　of　the　hypogastrium　at　different　volumes　of　the　bladder　is　obtained　by　simulation.　It　also　explains　the　causes　of　bladder　impedance　changes　based　on　the　current　density　distribution　and　designs　the　impedance　acquisition　circuit　to　carry　out　experimental　data　measurements　on　the　subjects.　The　results　show　that　changes　in　bladder　volume　affect　the　amplitude　and　phase　of　impedance　in　the　hypogastrium.　The　model　proposed　in　this　paper　can　provide　a　theoretical　basis　for　bladder　urine　volume　body　surface　monitoring.