The invention discloses a dual-circulation purification window. A window mullion is provided with an indoor-end air channel and an outdoor-end air channel. An outdoor air inlet is formed in the portion, at the lower end of the outdoor-end air channel, of the window mullion, and an air inlet door driven by a motor A to be opened and closed is installed at the outdoor air inlet. An outdoor air outlet is formed in the portion, at the upper end of the outdoor-end air channel, of the window mullion, and an air outlet door driven by a motor B to be opened and closed is installed at the outdoor air outlet. One filter screen set is installed at the position, at the air inlet, inside the outdoor-end air channel, an air inlet unit is installed inside the indoor-end air channel, the other filter screen set is installed at the upper end of the air inlet unit, and an internal circulation air door is installed at the upper end of the other filter screen set. An indoor air inlet is formed in the portion, at the indoor end of the air inlet unit, of the window mullion, and an electrostatic adsorption brush is installed on the upper portion of the indoor air inlet. An air outlet unit is installed at the position, at the air outlet, inside the indoor-end air channel, and an indoor air outlet is formed in the portion, at the indoor end of the air outlet unit, of the window mullion. Indoor air of a building with the dual-circulation purification window can be purified even if the window is closed, and air pollution inside the building is reduced.