（我们以删除 php-fpm 这个镜像为例子）
一、查看镜像的 ID
[root@localhost ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE docker.io/redis latest 36304d3b4540 3 weeks ago 104 MB docker.io/redislabs/rebloom latest ff42eae2d4fc 3 months ago 98.5 MB docker.io/feisky/php-fpm sp 65aa12240203 20 months ago 384 MB docker.io/feisky/nginx sp 915c06c73824 20 months ago 109 MB
（php-fpm 镜像ID 为：65aa12240203）
二、执行镜像删除命令： docker rmi IMAGE ID
[root@localhost ~]# docker rmi 65aa12240203 Error response from daemon: conflict: unable to delete 65aa12240203 (cannot be forced) - image is being used by running container 7ce6e056ebb3
这里，我们发现报错了是因为我们要删除的镜像正在被容器ID为：7ce6e056ebb3 的正在运行着。
（1）我们可以使用 docker ps -a 看一下：
[root@localhost ~]# docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PO NAMES 7ce6e056ebb3 feisky/php-fpm:sp "php-fpm -F --pid ..." About a minute ago Up About a minute phpfpm 6e740aa100ef feisky/nginx:sp "nginx -g 'daemon ..." 2 minutes ago Up 2 minutes 0.tcp nginx ba6392c9da69 redis "docker-entrypoint..." 12 days ago Exited (255) 13 hours ago 1279/tcp redis-server-6379 f29c1f1814a1 redislabs/rebloom "docker-entrypoint..." 13 days ago Exited (0) 13 days ago compassionate_aryabhata f5ed3ec05a9e redislabs/rebloom "docker-entrypoint..." 13 days ago Created blissful_nobel e212a66e1964 redislabs/rebloom "docker-entrypoint..." 13 days ago Exited (0) 13 days ago dreamy_jennings 2995bb0ef7b6 redislabs/rebloom "docker-entrypoint..." 13 days ago Created festive_shirley
可以看到容器ID为 7ce6e056ebb3 的已经在运行中。（Up About a minute）
（2）这时，我们需要先停止正在运行的容器，否则会出现如下情况：
[root@localhost ~]# docker rm 7ce6e056ebb3 Error response from daemon: You cannot remove a running container 7ce6e056ebb37062e7ed26ded5bff57a11b4d005193be35ca18d8bbc9307cb21. Stop the container before attempting removal or use -f
解决方法：（1）停止正在运行容器： docker stop 7ce6e056ebb3
最后执行删除容器操作： docker rm 7ce6e056ebb3
（2）强制删除正在运行容器： docker rm -f 7ce6e056ebb3
三、现在我们可以执行镜像删除 docker rmi IMAGE ID
[root@localhost ~]# docker rmi 65aa12240203 Untagged: docker.io/feisky/php-fpm:sp Untagged: docker.io/feisky/php-fpm@sha256:b3835a298915058f41cf4c01895dd6556b272f6035a77ce1dad1f0c39f37b19f Deleted: sha256:65aa1224020319c62d5f1045ecf096797ce0db3b895c4bf00d083a97e837bb3c Deleted: sha256:94f2d9ba77fcab9e8ef305324c0063450067753418a368d88f3983aca63e3802 Deleted: sha256:389a8a0e2506f7ddaa2bff3d1b23af2296c5fe4c1441dda68562dfd2e9f6ade0 ......
四、检查镜像是否删除成功 docker images
[root@localhost ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE docker.io/redis latest 36304d3b4540 3 weeks ago 104 MB docker.io/redislabs/rebloom latest ff42eae2d4fc 3 months ago 98.5 MB docker.io/feisky/nginx sp 915c06c73824 20 months ago 109 MB
我们可以看到 php-fpm 镜像已经删除成功。