Sichuan Province, a populous province in southwestern China with natural and economic disparities, displays significant population migration. This study examines the spatial characteristics of population migration in Sichuan Province using three National Population Censuses datasets since 2000. The results include (1) Sichuan Province experiences a notable net population outflow while Chengdu exhibits a solid inflow. (2) Intra-provincial population inflows are much more extensive than inter-provincial inflows. Chengdu and Panzhihua are the leading destinations that attract the population from other prefectures and Chongqing municipality. (3) Northeastern and southern Sichuan are the central regions experiencing population outflow to the Pearl River Delta and Yangtze River Delta regions. This paper also highlights the social changes resulting from population migration. The outflow areas face uneven economic development due to labor loss and aging; the hollowed-out villages lead to declining public services and further poverty in rural areas; and central cities like Chengdu encounter resource allocation challenges.