错误：A GUID Partition Table (GPT)

在终端运行

sudo diskutil
//启动diskutil，能够看到diskutil的所有命令。运行
diskutil list
//能够显示所有当前挂载的盘片,我的是这样的
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                 Apple_APFS Container disk1         121.1 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +121.1 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume pc                      114.4 GB   disk1s1
   2:                APFS Volume Preboot                 19.9 MB    disk1s2
   3:                APFS Volume Recovery                509.8 MB   disk1s3
   4:                APFS Volume VM                      2.1 GB     disk1s4

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *120.0 GB   disk2
   1:        Apple_partition_map                         32.3 KB    disk2s1
   2:                  Apple_HFS mac                     4.5 GB     disk2s3
//找到需要分区的，/dev/disk2 (external, physical)
//分区，diskname是你的盘片将来的名字
diskutil eraseDisk JHFS+ diskname disk2

成功！