1. diskutil apfs list
   
   这里的disk5s1是挂载的一张tf卡，结果被我使用mac的磁盘工具格式化为APFS格式了，我现在要讲其重新格式化为exFAT格式。
2. diskutil apfs deleteVolume /dev/disk5s1
   输出以下结果

Started APFS operation
Deleting APFS Volume from its APFS Container
Unmounting disk5s1
Erasing any xART session referenced by 5CEC7055-6985-4B7E-AAC2-62434BCD00E9
Deleting Volume
Removing any Preboot and Recovery Directories
Finished APFS operation

3. diskutil apfs deleteContainer /dev/disk5
   输出以下结果

Started APFS operation on disk5
Deleting APFS Container with all of its APFS Volumes
Unmounting Volumes
Deleting Volumes
Deleting Container
Wiping former APFS disks
Switching content types
1 new disk created or changed due to APFS operation
Disk from APFS operation: disk4s2
Finished APFS operation on disk5
Removing disk4s2 from partition map

4. diskutil list
   查看挂载的tf的标志符
   
5. sudo diskutil eraseDisk exFAT SDCARD MBRFormat /dev/disk4
   输出以下结果

Started erase on disk4
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk4s1 as ExFAT with name SDCARD
Volume name      : SDCARD
Partition offset : 2048 sectors (1048576 bytes)
Volume size      : 61065216 sectors (31265390592 bytes)
Bytes per sector : 512
Bytes per cluster: 32768
FAT offset       : 2048 sectors (1048576 bytes)
# FAT sectors    : 8192
Number of FATs   : 1
Cluster offset   : 10240 sectors (5242880 bytes)
# Clusters       : 953984
Volume Serial #  : 66309196
Bitmap start     : 2
Bitmap file size : 119248
Upcase start     : 6
Upcase file size : 5836
Root start       : 7
Mounting disk
Finished erase on disk4

6. diskutil list
   重新查看硬盘情况
   
   即可。