First you really need to figure out WHY he is rushing. Do you have a friend that can try him, that is either REALLY good (not saying you aren't) or knows NOTHING about his rushing?
My sister's event horse rushes jumps really bad but he is naturally a very calm horse. And after alot of struggling, she's realized that it is her making him rush. She had a friend who knew nothing about him get on him and he jumped like a hunter, and was ALMOST lazy. The Problem is she was pulling on him on the approach, trying to keep him from rushing. This is what you DO NOT want to do. She took a lesson from Kim Severson, and though its taken her ALOT of time to work through it, he is a completely different horse. Kim had her loosen her reins and bridge her reins so she could NOT pull on him at all. It is really a miracle how well he jumps with her now.
Then there are the horses that are just naturally hot-headed and more energetic horses. This is my event horses' problem. He gets worse the more I pull but he is also just naturally like that, whereas my sisters horse is always so laid back. What I find works best with him is walking jumps. Set up a course of about 2' or lower and walk the course. About 2 strides out from the jump, let him pick up a trot, then halt after the jump, and continue at a walk to the next one. I did this with my horse for a few weeks and it worked GREAT. If he gets hyped up again, go walk a few jumps.
Make sure your horse is not on the forehand going to the jumps and your not using too much hand. This is hard to believe but you really should use MORE leg on a rusher. My horses' previous owner used spurs on him for jumping and I thought he was insane, but now I'm starting to understand why. You need to push him forward from back to front, into a connection when your jumping, just like dressage. When a horse is on the forehand, they almost have to rush the jump in order to catch up with themselves and make it over the jump.
Another thing you can try is doing a slight leg yield all the way down to the jump, this also worked great with my horse. Seems kinda odd at first, but it does work.