The invention discloses an axial flow fan with blade suction surfaces having vortex breaking structures and with grooves formed in blade tops. The vortex breaking structures are additionally arranged on the portions, close to roots, of the suction surfaces of blades of an impeller, the airfoil grooves are machined in the tops of the blades, a labyrinth seal structure is additionally arranged in the clearance between a hub and an inner barrel, rectangular grooves are machined in the tails of the suction surfaces of guide vanes, the size of channel vortexes in an impeller passenger can be restrained, and radial secondary flow is reduced. Development of leakage flow can be impeded, mixing of the leakage flow and main flow is weakened, and therefore leakage losses of the blade tops are reduced. A high throttling effect can be generated, the stability of airflow on an outlet of the impeller is improved, and the leakage amount of airflow at the roots of the blades is reduced. The thicknesses of boundary layers on the tails of the guide vanes can be well controlled, separation of the boundary layers is avoided, disengagement of the vortexes is restrained, and the disengaging frequency of the vortexes is reduced. By improving different positions of the axial flow fan, the axial flow fan is higher in efficiency, lower in noise and more environmentally friendly and saves more energy.