Enhanced　external　counterpulsation　(EECP)　is　a　noninvasive　treatment　method　for　coronary　artery　atherosclerosis　that　acts　on　the　vascular　endothelial　cells.　The　intracoronary　hemodynamic　parameters　that　influence　long-term　treatment　effect　are　the　fundamental　factors　for　the　inhibition　of　intimal　hyperplasia,　which　cannot　be　measured　in　real　time.　In　order　to　optimize　the　long-term　treatment　effect　of　coronary　heart　disease,　it　is　necessary　to　establish　a　method　for　quantified　calculation　of　intracoronary　hemodynamic　parameters　during　counterpulsation　to　research　the　long-term　hemodynamic　mechanism　of　EECP.　A　geometric　multiscale　model　coupled　by　the　zero-dimensional　(0D)　lumped　parameter　model　and　the　three-dimensional　(3D)　model　of　narrow　coronary　artery　was　established　for　the　simulation　of　intracoronary　hemodynamic　environment.　The　3D　model　was　used　to　calculate　the　hemodynamic　parameters　such　as　wall　shear　stress　(WSS)　and　oscillatory　shear　index　(OSI),　while　the　0D　model　was　used　to　simulate　the　blood　circulatory　system.　Sequential　pressure　was　applied　to　calves,　thighs,　and　buttocks　module　in　0D　model　with　the　consideration　of　vessel　collapse.　Hemodynamic　performance　was　compared　with　clinical　reports　to　verify　the　effectiveness　of　the　method.　There　were　significant　increases　of　the　diastolic　blood　pressure　(DBP),　coronary　flow,　and　the　area-averaged　WSS　during　application　of　EECP,　while　OSI　behind　stenosis　has　some　decrease.　The　waveforms　of　coronary　flow　has　good　similarity　with　the　clinical　measured　waveforms,　and　the　differences　between　calculated　mean　arterial　pressures　(MAPs)　and　clinical　measurements　were　within　1%.　The　fundamental　factor　in　the　cure　of　coronary　heart　disease　by　EECP　is　the　improvement　of　WSS　and　the　decrease　of　OSI.　Comparing　with　the　clinical　reports,　the　immediate　hemodynamic　changes　demonstrate　the　effectiveness　of　model.　Intracoronary　hemodynamic　parameters　during　EECP　could　be　acquired　and　the　method　could　be　used　to　simulate　the　long-term　treatment　effect　of　EECP.