use md5 /path/iso and compare the md5 sum.
try to mount the iso(most likely not working cos when i tried, it gave me no mountable file system)
if not use external software from app store like the rar extractor free to extract it.
i am using a late 2013 retina 13inch pro and i had no issues.
when you extracted the iso, you will find this app called deepen boot maker inside a zip file with the same name(copy it to your application folder is u wish)
use that and create the usb.

press option key during boot up and you will see 2 yellow volumes called windows(mac firmware tend to name every os that is not os x as windows, it is deepin) and efi.
select the efi volume and u will see grub
hit enter and proceed, if you are still stuck please provide more info about your mac, other than the os x
it is possible to have a uefi loader(deepin provide that, click expert partition and click uefi)
all done, i don't expect it to provide sth like grub, but it may cause deepen to be the primary boot os
and u can't change it in startup disk
so one tip
press option key, you will find volumes, the deepen will be in the form of a hard disk partition called windows(you can rename it using the bless command if os x can read the file system, i have nor tried deepen on my mac unless the 15.1 comes out, since retina will then be supported)
when you does that, select macintosh hd, press the control key, and you will see the arrow becomes a circle, hit enter and you can set it as primary os
if not, you may want to install external boot loaders like refind, which requires the sip to be disabled, so boot into the recovery partition and run csrutli disable)
good luck

Thank you. I have a mid 2009 mbp so I'm thinking that may be the problem (if it is too old). I used the deepin boot maker and refind. When booting the Linux volume shows up, my problem is when I select it the computer gives me the option to install deepin but once I choose that option the deepin startup page (black screen with the word deepin filling up with water) appears but the screen freezes here and won't go any further. I will check the md5 when I get a chance but it will be a few days before I have access to my computer.

Also is grub where it gives the option to install? Because I don't get to the point where I can click expert partition.

okay, you can only get to the expert mode after the booting process, i am not sure but does it use intel chips?
and does it have open firmware?

Yes it has an Intel duo 2 core processor and open firmware

No sorry the computer has EFI

okay, try pressing the option key, do not use refind unless necessary.
and how much ram?
deepen requires better hardware to run, just wait a while and see.

I was using just the option key at first but when that didn't work I installed refind. I just installed 8gb of ram so that shouldn't be a problem. Since this is my first time trying to instal Linux when I get back to my computer I'll try installing a different distro to make my problem isn't with Linux in general then try deepin again.

hmm, did you select the efi volume?
i suggest debian.

Yes. Okay I'll try Debian thanks