The Red-crowned Crane (Grus japonensis) is a species unique to Asia, with a global population of about 3430. It was a Class I protected wild animal in China and was listed as vulnerable on the World Conservation Union (IUCN) Red List. The Red-crowned Crane was at the top of the food chain of wetland ecosystems and was one of the flagship species for wetland biodiversity conservation. In the past 40 years in China, with the rapid development of the economy, a large number of wetlands had been reclaimed and developed, which had a serious negative impact on the population of Red-crowned Cranes. This study used multi-source data collation and field observation to obtain the habitat distribution data of Red-crowned Cranes in the past 40 years. By integrating land use datasets, we used circuit theory to identify potential ecological corridors for Red-crowned Crane migration. Our results provided that from 1980 to 1990, the Red-crowned Crane had a wide distribution area, a large number of habitats. There were as many as 15 habitats with more than 50 Red-crowned Cranes. From 1991 to 2000, records of Red-crowned Cranes have dropped dramatically, and the habitat network structure tended to be simpler. From 2000 to 2020, the distribution area of Red-crowned Cranes continued to shrink, the number of Red-crowned Cranes and their habitats continued to decrease. Red-crowned Cranes were concentrated in a few habitats (there were only 5 habitats with more than 50 Red-crowned Cranes). The wintering habitats of Red-crowned Cranes showed a trend of moving northward. This study showed the distribution characteristics, spatiotemporal dynamic evolution, and driving factors of the Red-crowned Crane habitats over the past 40 years at the national scale, providing basic support for the habitat protection and population restoration of the Red-crowned Crane.