Option One: This really isn't a problem. The other players aren't complaining, and so we can see that this is not really that big a deal. Relax, go with the flow, and chuckle along with the group when a 60-pound block of stone drops on his head, the player and stone both freeze briefly, and then the stone splits cleanly down the middle and the fighter carries on as if he hasn't even noticed.
(Obviously this option is written in the form of assuming itself to be true. If the assumptions are wrong, then so is the rest of this option.)
If he is effectively-immune to the traps, due to the nature of the traps (not dealing significant enough damage, having no lasting effects, etc), then the immediate problem is the nature of the traps.
- Poison traps (ongoing damage)
- Crippling traps (reduced speed, reduced ability to fight, etc)
- Ability-damage traps (especially Con - attack the source of the HP...)
- Trapping traps (Making him stuck until the trap is disarmed, possibly taking ongoing damage as he struggles.)
- Movement traps (that send him somewhere else)
If he doesn't get the hint, double them up. Get him stuck in a trap that causes ongoing Con damage after dropping him into a pit. And then suddenly the rat-swarm surges out of the little holes in the walls, and he can't move to defend himself. But that's ok, the lowering ceiling with the poisonous spikes embedded in it will crush all the rats that stick around.
"Ok fine. How much damage?"
"All of it. It kills you."
"Yea but how much--"
"Every single hp. Take all the HP you have left, then add all the possible amount of damage you could resist with your best rolls, then add a hundred for a safety margin, and then double it just because you asked twice. And then the flame-jets start up, to take care of anything left."
"It's too bad, the rogue would have spotted it easily, if you hadn't just gone tramping down the hall like a dire-elephant."
ehem! "Suddenly you jerk to wakefulness, slowly realizing it was a dream. But it lingers in your mind. If -you- could think of such a horrifying trap, what would stop others from doing so?"
A party's resources are finite. The casters only have so many spell slots they can prepare healing spells in. The Wands of Cure Light will run out eventually. The portable hole full of potions still has a certain real number of potions in it. You can only take 1 Long Rest per day. And so on.
If you change the nature of the traps to very-high damage, but low-DC to spot and disable, it clearly becomes a matter of one character disproportionately using up the party's recovery resources at an artificially high rate, when it would require less (or none) if the party didn't simply blunder straight into every trap.
Option Three: Invert the question! (bet you thought it was done after that wall of text!)
So we can all see that the player quite happily marches face-first into every trap he can. But why is he doing this?
Is he metagaming? "Based on the math, I'm too strong to fail, and just tripping on the trap gets it out of the way the fastest!"
Is he playing a role? "What, you didn't know I had 6 Wisdom? Yea, he thinks it's a really smart and efficient way to handle it. He just can't process the cause and effect relationships of "always getting hurt" as being caused by "walking into traps face-first."
Is the rest of the party unable to act effectively without him stepping into bulldozer mode? If the rest of the party is just spending vast parts of each session talking about how to deal with a minor problem in front of them ("is this door trapped?" This isn't about major plot points) then they probably need a kick in the butt.
Is he lacking some other more appropriate opportunities to "show off"? Is there a balanced amount of combat in the game, where he can show off what a good fighter he is?
All of these are things you should talk to the player about, if you haven't already.