A hemodialysis machine comprises a heating water tank, a dry powder cylinder A, a dry powder cylinder B, a pump A, a pump B, a balance cavity, a heparin pump, a blood pump, a dialyzer and a heat exchanger. The heating water tank heats reverse osmosis water, hot reverse osmosis water is made into saturated liquid A and saturated liquid B through the dry powder cylinder A and the dry powder cylinder B respectively, the pump A and the pump B extract liquid in the dry powder cylinder A and the dry powder cylinder B out to the balance cavity, mixing is carried out in the balance cavity, dialyzate is obtained, the blood pump extracts blood of a human body, the blood is mixed with heparin pushed by the heparin pump, the dialyzer carries out dispersion convective activity on the dialyzate and the blood which are subjected to exchanging, the blood after exchanging flows back to the human body, the dialyzate after exchanging flows back to the balance cavity, and after in-out balance is achieved, discharging is carried out though the heat exchanger. According to the hemodialysis machine, the dry powder cylinder A, the dry powder cylinder B and the balance cavity are used for effectively achieving the fact that powder A and powder B are used for hemodialysis, and the cost of the hemodialysis machine is lowered.