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.