This disclosure provides a data backup method, an electronic device, and a storage medium. According to the method, in a current backup, a file list in a previous backup is obtained, the local file list in the previous backup is compared with a local file list in the current backup, to find an added file and a modified file, the added file and the modified file are uploaded to a cloud server for backup, and an identical file is not repeatedly uploaded to the cloud server for backup. When the added file and the modified file are backed up, different processing manners may be used for a regular file, a small file, and a large file.