Try all the boot disks proposed in the boot menu. There is a high chance one of them will be booting into GRUB, just fine.
If it still does not work, then I suppose the easiest way is to make sure that GRUB is installed properly, by e.g. re-installing Deepin and making sure it actually installs GRUB correctly.
Additionally, if you are on a UEFI system, then you need an EFI partition, which is always separate from the root partition. So if you only created the latter, the boot won’t work, as you are experiencing right now.
Sometimes, there is an option to boot from the USB drive in UEFI mode, too. Look out for that option. Sometimes this option does not appear, if the ISO isn’t burned the right way onto the USB drive.
To fix the last proposal, you need to boot into Windows by selecting the Windows Boot Manager in the boot menu in the UEFI, get Rufus and burn the disk in UEFI and DD mode. Then try again.
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