Image upgrade method and device

An image upgrade method is provided. The method includes: receiving an incremental image file of a container, where the incremental image file includes a newly-added file, a modified file, and information about a deleted file, and the information about the deleted file includes a name of each deleted file and a storage path of the deleted file; updating an original image layer based on the incremental image file to obtain an updated image layer, where a state of the deleted file is set to a hidden state at the updated image layer; and overlaying a file at the updated image layer with a file at a container data layer to form an updated unified view at a view layer for use by the container, where the updated unified view does not include the deleted file whose state is set to the hidden state.