Is there any way to prevent dragon attacking Windhelm when you return from Solstheim?

I'm level 20 and there's a Blood Dragon every time I return to the mainland.
I can beat it eventually but problem is that the dragon butchers all the NPCs around, and most of the time goes to the main bridge and the farms nearby. If I go inside Windhelm the damn dragon follows me inside.

Never had this bug.Try fast travelling directly from Solstheim.
First be at a place that isn't in Eastmarch, fast travel to Solstheim, then fast travel back.

That lands you at the Windhelm docks.

How far are you during both Main Quests?

I believe dragon spawns are set on a timer. So fast travel around Solstheim until you get a dragon spawn (needs to be a random dragon, not one of the ones that live at a fixed location). Once you get your random dragon spawn, you should be safe to return to Windhelm.

I've never had that problem either but a somewhat related problem that i've been encountering is that when i fast travel to Solitude there's always a freshly killed dragon just inside the city gates. It's head falls on me every time.

This won't avoid the attack, but I've found if you get the dragon's attention and then sprint away from NPCs, it'll tend to follow you.

whenever i tame a dragon on solstheim it follows me to skyrim

This is precisely the reason why I never start the main quest normally, Dragonborn forced me to and I've been stuck with problems like this since. I whipped myself up a mega overpowered bow using the restoration loop so I can one-hit dragons when they start pestering me and my NPCs.

Not sure what you can do to remove the dragon, have you completed the main quest yet?

I thought you can only fast travel to Windhelm from Solstheim?

That happened to me, but it was no worry. The Khajiit were there. They and the guards and Illia and I made dragon sushi out of it. And I needed to unlock the Bend Will shout.

How odd.

if you dont want the dragon to kill any NPC's just use the bend will shout on it ..or like stated above, create a really overpowered bow simply to kill pestering dragons when you run into any

You take the boat. I never fast-travel out of Solstheim, and I haven't got a dragon in Windhelm yet.