The 65-year-old began coaching the All Blacks in 2004 and has gone on to win 84 out of 99 matches.
"It's special and I'm very proud of that," said Henry.
"To do that 100 times is also special but probably also a sign of madness as well. It's a privilege to be involved in the most successful sporting team in the history of sport over 110 years."
New Zealand are currently top of Group A with 15 points.