The　development　of　hydrogen-fueled　Wankel　rotary　engine　is　restricted　by　the　leakage　problem,　especially　the　apex　seal　leakage　(ASL).　In　the　study,　the　ASL　area　is　divided　into　the　geometric　leakage　area　(GLA)　and　the　dynamic　leakage　area　(DLA).　The　models　of　under-seal　pressure　prediction　and　vibration　of　apex　seal　are　established.　The　mechanism　of　GLA　and　DLA　and　the　effects　of　key　parameters　on　them　are　analyzed.　Results　show　that　the　DLA　decreases　with　the　increase　of　discharge　coefficient,　clearance　between　apex　seal　and　slot.　There　is　no　DLA　when　the　rotation　speed　is　slower　than　2000　rpm　or　higher　than　7000　rpm.　Besides,　the　value　of　DLA　is　only　11.23%　of　GLA　and　the　GLA　can　be　reduced　by　88.57%　when　using　a　corner-piece　structure.　The　total　leakage　decreases　with　the　increase　of　rotation　speed.　Finally,　some　measures　to　reduce　the　leakage　are　given.(c)　2022　Published　by　Elsevier　Ltd　on　behalf　of　Hydrogen　Energy　Publications　LLC.