Can I fly my drone above the Great Wall?

Yes, you can fly your drone above the wall. You may google William Lindesay, who did the same thing. Good luck!

As of 07/07/2019, you cannot fly a drone at the great wall. Unfortunately, this information doesn't seem to be available in English anywhere but if you search in Chinese on Baidu (Chinese Google), you'll see that it's not allowed. I was on travel with my wife (who is from China) and I brought the drone with me to the wall but we didn't see anybody else flying so she searched and sure enough it's not allowed. That being said, most likely nobody will bother you but China isn't really the place a foreigner would want to get caught doing something illegal.