A counter-rotating fan, comprising: an impeller assembly, the impeller assembly comprising a first stage impeller and a second stage impeller rotating around an axis of the counter-rotating fan, which defines an axial direction, a rotation direction of the first stage impeller and a rotation direction of the second stage impeller being opposite to each other, the first stage impeller comprising a first hub and a plurality of first blades connected to the first hub, the second stage impeller comprising a second hub and a plurality of second blades connected to the second hub, pressure surfaces of the first blades facing toward suction surfaces of the second blades, each of the first blades bending toward the rotation direction of the first blades in a direction from a blade root to a blade tip of each of the first blades, each of the second blades bending toward the rotation direction of the second blades in a direction from a blade root to a blade tip of each of the second blades; and an air guide structure, the air guide structure comprising an air inlet grille, the air inlet grille being arranged adjacent to the first stage impeller, the air inlet grille comprising a plurality of supporting guide vanes arranged in a circumferential direction, characterized in that: the supporting guide vanes bend from a root to a tip of the supporting guide vanes in a direction opposite to the rotation direction of the first blades; the supporting guide vanes bend in a direction toward an air outlet side, and an inlet installation angle of each of the supporting guide vanes being smaller than an outlet installation angle of each of the supporting guide vanes, wherein the inlet installation angle and the outlet installation angle are referenced to the axial direction; and an axial width of each of the first blades is at least 1.4 times an axial width of each of the second blades, and is at most 3 times the axial width of each of the second blades. an impeller assembly, the impeller assembly comprising a first stage impeller and a second stage impeller rotating around an axis of the counter-rotating fan, which defines an axial direction, a rotation direction of the first stage impeller and a rotation direction of the second stage impeller being opposite to each other, the first stage impeller comprising a first hub and a plurality of first blades connected to the first hub, the second stage impeller comprising a second hub and a plurality of second blades connected to the second hub, pressure surfaces of the first blades facing toward suction surfaces of the second blades, each of the first blades bending toward the rotation direction of the first blades in a direction from a blade root to a blade tip of each of the first blades, each of the second blades bending toward the rotation direction of the second blades in a direction from a blade root to a blade tip of each of the second blades; and an air guide structure, the air guide structure comprising an air inlet grille, the air inlet grille being arranged adjacent to the first stage impeller, the air inlet grille comprising a plurality of supporting guide vanes arranged in a circumferential direction, characterized in that: the supporting guide vanes bend from a root to a tip of the supporting guide vanes in a direction opposite to the rotation direction of the first blades; the supporting guide vanes bend in a direction toward an air outlet side, and an inlet installation angle of each of the supporting guide vanes being smaller than an outlet installation angle of each of the supporting guide vanes, wherein the inlet installation angle and the outlet installation angle are referenced to the axial direction; and an axial width of each of the first blades is at least 1.4 times an axial width of each of the second blades, and is at most 3 times the axial width of each of the second blades. the supporting guide vanes bend from a root to a tip of the supporting guide vanes in a direction opposite to the rotation direction of the first blades; the supporting guide vanes bend in a direction toward an air outlet side, and an inlet installation angle of each of the supporting guide vanes being smaller than an outlet installation angle of each of the supporting guide vanes, wherein the inlet installation angle and the outlet installation angle are referenced to the axial direction; and an axial width of each of the first blades is at least 1.4 times an axial width of each of the second blades, and is at most 3 times the axial width of each of the second blades.