Regarding the firmware issue of the TP-Link Archer C2600, because I accidentally completely damaged the firmware, the device is now completely unresponsive, and I want to use programmer firmware to repair it.
Archer C2600 | AC2600 Wireless Dual Band Gigabit Router | TP-Link
If my TFTP function is also abnormal, can I use this method to roll back? 
it's worth trying, considering it's a lot easier than rewriting the flash chip.
unless you messed up the flash chip completely, and wiped it, it should work.
writing directly to flash could work, assuming you can get your hands on a dump file.
hoping for the TFTP to be functioning normally. If it's not, the only option left might be to resort to programmer firmware.