Hemodialysis machine is divided into two parts: blood monitoring and alarm system and dialysis fluid supply system. The blood monitoring and alarm system includes blood pump, heparin pump, arterial and venous pressure monitoring and air monitoring, etc.; the dialysate supply system includes temperature control system, liquid dispensing system, degassing system, conductivity monitoring system, ultrafiltration monitoring and blood leakage monitoring and other components. Its working principle is as follows: the concentrated liquid for dialysis and dialysis water are made into qualified dialysis liquid through the dialysis liquid supply system, and then pass through the hemodialyzer to carry out solute dispersion, infiltration and ultrafiltration with the patient's blood induced by the blood guardianship alarm system; the patient's blood returns to the patient's body after the action through the blood guardianship alarm system, and at the same time, the liquid used for dialysis is discharged as a waste liquid by the dialysis liquid supply system; the cycle is repeated to complete the whole dialysis system. At the same time, the liquid used for dialysis is discharged from the dialysis fluid supply system as waste liquid.