The invention discloses a window blind air purification device which comprises a window blind, lifting ropes, a filter net and a window blind frame. Each blade of the window blind is composed of a permanent magnet and an outer shell wrapping the permanent magnet, and the blades are connected with the window blind frame through rotary shafts on the two sides; the two lifting ropes are connected with the end surfaces of the blades to adjust the rotating angle of the blades, and the filter net is arranged in parallel with the window blind; and every two blades can form a magnetic field of which the magnetic induction line is perpendicular to the two blades, due to the magnetic effect, fine particles in air can generate the magnetic flocculation effect to form large particles, and the large particles cannot pass through the filter net. The window blind air purification device has the advantages that through the permanent magnets, the magnetic fields perpendicular to the blades are generated so that the particles passing through can flocculate into large particles under the magnetic effect, and then the large particles are filtered out after passing through the subsequent filter net, so that the particles entering into a room are few, and the purpose for indoor air purification is achieved.