Abstract: To solve the problem of redundant Docker images caused by container migration during the process of live migration of Docker containers, the characteristics of the union filesystem container layer files and image layer files was used in this paper to be uniformly displayed by federation, and the files manipulated in the container existing the container layer. A Docker container online migration program was proposed. The program migrated container data only by migrating container layer data, which effectively avoided redundant Docker image generation. Based on the above design program, the verification experiment on the two most representative types of union filesystem storage drivers (aufs and overlay2) was completed. Results show that during the container migration, it not only enables the migration of container data, but also does not produce redundant Docker images.