Phylodynamic methods have successfully been used to describe viral spread history but their applications for assessing specific control measures are rare. In 2016-17, France experienced a devastating epidemic of a highly pathogenic avian influenza virus (H5N8 clade 2.3.4.4b). Using 196 viral genomes, we conducted a phylodynamic analysis combined with generalised linear model and showed that the large-scale preventive culling of ducks significantly reduced the viral spread between départements (French administrative division). We also found that the virus likely spread more frequently between départements that shared borders, but the spread was not linked to duck transport between départements. Duck transport within départements increased the within-département transmission intensity, although the association was weak. Together, these results indicated that the virus spread in short-distances, either between adjacent départements or within départements. Results also suggested that the restrictions on duck transport within départements might not have stopped the viral spread completely. Overall, by testing specific hypothesis related to different control measures, we demonstrated that phylodynamics methods are capable of investigating the impacts of control measures on viral spread.