There are three main types of access to dialysis: 1, autologous arteriovenous endovascular fistulae; 2, artificial blood vessels; and 3, catheters. Inadequate blood flow on dialysis depends first on which type of vascular access it is.1. If it is a catheter, especially the implantation of a long-term catheter with a CUFF, the most common cause of inadequate blood flow due to a long-term catheter is thrombosis. The catheter is implanted inside a large vein, and the presence or absence of thrombosis and wall adherence of the catheter can be examined by angiography. If there is stenosis or thrombosis, thrombolytic therapy or even dilatation can be performed to improve the flow of the catheter. If this is not possible, the catheter should be removed.2. Endolimbic fistula, is also the most widely used and recommended type of vascular access. If the blood flow is insufficient, first use ultrasound or DSA to understand the situation of the whole blood vessel, whether there is stenosis, whether there is thrombosis. If there is stenosis and thrombosis, balloon dilatation can be used to increase dialysis blood flow, and autologous arteriovenous endovascular fistula can be reconstructed if necessary.3. If there is artificial blood vessel, if the blood volume is insufficient, it is still necessary to consider whether there is thrombosis. If there is thrombosis, first thrombolysis, if necessary, reconstruction of artificial blood vessels.