A wind power generation apparatus, a tower and a method for suppressing a tower shadow effect of the tower. The tower is provided with suction through holes extending through a circumferential wall thereof, and the suction through holes are distributed in a circumferential direction of the tower; the tower is further provided with a suction apparatus, and the suction apparatus can perform suction to the suction through holes from outside to inside. With the tower and the method, when the suction through holes at a windward side are suctioned, the adverse influence of the tower shadow effect can be weakened or eliminated, a service life of a pitch varying bearing can be prolonged, a noise can be reduced and a wind energy utilization coefficient can be improved. When the suction through holes at a position of a bypassing flow detachment are suctioned, vortex-induced vibrations can also be suppressed.