Objective：To explore the value of autogenous arteriovenous fistula（AVF）stenosis assessed by ultrahigh frequency（UHF）ultrasound combined with B-Flow for insufficient flow in hemodialysis patients. Methods：From November 2017 to May 2020，a total of 114 hemodialysis patients with AVF stenosis in our hospital were selected for a retrospective study. UHF ultrasound combined with B-Flow examination was performed to observe and to detect the residual inner diameter，peak systolic velocity（PSV），peak systolic velocity ratio（PSVR）and blood flow of the fistula stenosis. After correlation analysis，the diagnostic efficacy was analyzed by receiver operating characteristic（ROC）curve. Results：The ultrasonography of AVF stenosis showed that the inner diameter of the dialysis access reduced，the blood flow bundle became thinner，and the flow velocity increased. The inner diameter of the fistula stenosis was positively correlated with the blood flow（r=0.761，P < 0.000 1）. There was no correlation between the PSV of the stenosis and the blood flow. The PSVR of the stenosis was negatively correlated with the blood flow（r=-0.457，P < 0.000 1）. The correlation coefficient between the residual inner diameter and the blood flow was greater than that between the PSVR and the flow（Z=3.762 7，P=0.000 2）. The area under curve（AUC）of the residual inner diameter of the fistula stenosis for diagnosing insufficient blood flow was 0.880（95%CI=0.809~0.936，P < 0.000 1），the optimal cut-off value was 1.0 mm，the sensitivity was 82.22% and the specificity was 84.06%. The AUC of PSVR of the fistula stenosis for diagnosing insufficient blood flow was 0.767（95%CI=0.678~0.841，P < 0.000 1），the optimal cut-off value was 4.9，the sensitivity was 73.33% and the specificity was 72.46%. The AUC of the residual inner diameter of the fistula stenosis for diagnosing insufficient blood flow was significantly greater than that of PSVR（P=0.008 2）. The AUC of combined diagnosis for insufficient blood flow was 0.883（95%CI=0.809~0.936，P < 0.000 1），which was significantly greater than the AUC of PSVR of the fistula stenosis for diagnosing insufficient blood flow（P=0.0017）. Conclusion：The residual inner diameter is more effective than PSVR in diagnosing insufficient blood flow，which can be used as an efficient method to provide guidance for early clinical interference.