Abstract: A device and method can be used for clinical virus inactivation treatment to automatically, continuously and cyclically treat plasma of a patient in a closed system. The disclosed plasma treatment device may be used for an anti-viral agent such as, for example, methylene blue photochemical plasma virus inactivation. The plasma treatment device can perform real-time treatment to the plasma in the closed system on the basis of the principle of plasma exchange and can realize real-time back-transfusion during treatment.