We study effect of additive Lévy noise and periodic force on dynamics of spiral waves,which appears in a FitzHugh-Nagumo excitable system.Motion of spiral tip changes regularly with external force period in domains,which can be explained with corresponding Fourier spectrum.A regular change is due to the existence of frequency-locking.Lévy noise sequence contains large-scale noise with a small probability.Large-scale noise has main effect on the motion of spiral tips.We pointed out that effect of Lévy noise on tip motion depends on period of external force.At appropriate parameters,the Lévy noise leads to the disappearance of spiral waves,and it offer a methold of controling and eliminating spiral waves.The locking behavior between internal period of the system and external modulation period is analyzed.Arnold tongues is obtained at various noise intensities.They indicate existance of stochastic resonances.