World number one Serena pounded the Belgian third seed from the baseline to avenge her acrimonious defeat to Henin in the French Open semi-finals four weeks ago.
The American, who will face either elder sister Venus or Kim Clijsters in the final, galloped to a 4-0 lead in the first set in just 20 minutes after Henin failed to take advantage of two break points in the opening game.
But the Belgian threatened to come back into the equation after breaking the menacing Serena serve twice on the trot.
An uncharacteristic backhand error on break point in the eighth game swung the match back the
"I played really well today -- I was really focused, I mean I had to be," said Serena, who had been beaten by Henin in their last two meetings.
"I'm just happy to be in the final of Wimbledon again, I'm really excited. It's a great feeling. I just have another opportunity to have another go at a championship here, but either way making the final is a big deal for me.
"I don't know, Venus is playing brilliant here but so is Kim. She's playing great, she's been playing great for a long time now so it's going to be another great semi-final.
"I'll sit and watch it and take notes so whoever I play I will be able to do pretty well."