In recent years, under the background of a series of national development strategies and the transformation of economic geography patterns, the connections between cities, towns, and rural areas in China have become increasingly close, bringing about a more diversified population distribution than before. However, there are still few studies that simultaneously involve the spatial analysis of cities, towns, and rural areas, as well as the evolution patterns and underlying mechanism of population distribution in regions with different levels of development. Based on the data of the sixth and seventh national censuses (provincial data of Jiangsu Province), this study explored the spatiotemporal evolution of city, town, and rural population distribution and revealed the influencing factors of the comprehensive attraction of city-town-rural areas to the floating population in Jiangsu Province from 2010 to 2020. The results show that: 1) In the past 10 years, Jiangsu Province maintained a population spatial distribution pattern of dense in the south and sparse in the north, but the changes in the size of the resident population and floating population have shown noticeable geographical differences, which is manifested in the continued high growth rate of resident population in south Jiangsu, but the high growth rate of floating population is concentrated in central and north Jiangsu. 2) In the past 10 years, the high-value area of the ratio of floating population to resident population was still concentrated in south Jiangsu. The proportion increased in all cities and some towns in central and north Jiangsu, as well as slightly in some rural areas in south Jiangsu. 3) Comprehensive exploration of changes in the population distribution of the city-town-rural areas has found that although the trend of common growth of resident population in the three types of space was not obvious, the ratio of floating population to resident population in more than half of counties and cities showed the characteristics of city-town-rural area common growth. The increase in the comprehensive index of citytown-rural area attraction to floating population in central and north Jiangsu exceeded that of south Jiangsu. 4) Public affair investment of the government and regional industrial development had a significant positive impact on the comprehensive attraction of city-town-rural areas to floating population, which had a stronger effect in economically developed areas and areas with stronger industrial base. In contrast, advanced industrial structure only had a positive effect in south Jiangsu. Based on the correlation between the change in population distribution and the level of regional urbanization, as well as the analysis of its spatial distribution characteristics and influencing factors in city-town-rural areas, this study put forward specific suggestions for the urban-rural integrated development of the population in different counties and cities.