<p>Existing studies have mainly treated urban migrants as a homogeneous group, while the comparison between highly-skilled and less-skilled migrants regarding their permanent settlement intention across city size has received inadequate attention. Our study examines the skill heterogeneity in migrants’ permanent settlement intention across city size in China and its determinants in 2017. The results observe that the larger the city size, the higher the permanent settlement intention of both highly-skilled and less-skilled migrants, which are different from that, the likelihood of acquiring urban hukou status for highly-skilled and less-skilled migrants to achieve their permanent settlement formally through local government talent policies and new urbanization policy, decrease as city size increases. Furthermore, these between-cities changes in permanent settlement intentions of both highly-skilled and less-skilled migrants can be attributable to that the pull effect of individual wage levels on the permanent settlement intentions of both migrant groups increases gradually with the rise of city size. However, permanent settlement intention of highly-skilled migrants is significantly higher than that of less-skilled migrants in large cities. This is primarily because the inhibitory effect of an agricultural hukou status on less-skilled migrants’ permanent settlement intention in large cities is significantly stronger, while the promoting effect of both social integration and wage levels on the permanent settlement intention of less-skilled migrants in large cities is significantly weaker, relative to highly-skilled migrants. These findings contribute to understanding the existing theories on the skill heterogeneity of migrants’ settlement intention and its motivation.</p>