The invention relates to a portable blood purifying system, which comprises a high throughput dialyzer with an arterial duct, a venous duct, a washing liquid tube and a transfusion tube; the arterial duct is in turn connected in series with an arterial valve, an arterial pressure sensor and a blood pump; the venous duct is in turn connected in series with a venous valve, a venous temperature sensor, a venous bubble detector and a venous pressure sensor, so that an external circulation unit is formed; the washing liquid tube is connected in series with a pre-charging valve and is communicated with a washing liquid container; the transfusion tube is in turn connected in series with a temperature controller, a transfusion tube bubble collector and a transfusion pump, and is communicated with a waste liquid container, so that a waste liquid processing unit is formed; and the system also comprises a transfusion pump, a temperature control device, a transfusion tube, a gating valve and a first transfusion branch and a second transfusion tube branch, so that a transfusion unit is formed. The system is simplified in structure and convenient to carry; and the system is suitable for patients to do short-time dialysis for several times or night dialysis treatment at home as household treatment equipment, so that toxin tolerance of dialysis patients during dialysis period is relieved while medical cost is reduced.