The International Rugby Board has approved a trial in South Africa's Currie Cup that extends the jurisdiction of the television match official.
The TMO there is able to rule on any infringement in the build-up to a try, rather than just the act of scoring, as is the current situation.
Asked whether he backed the idea, Henry said: "Totally. Any technology that is going to support correct decisions I will be totally supportive of.
"I am sure the players would be too. It is a major problem with the game at the moment and we need to try to get those things right.
"I just think if we can improve the quality of decision-making in the game it would be helpful. Just like it is difficult for players, it is difficult for referees and if we can assist them that would be good."
English referee Wayne Barnes received widespread criticism in New Zealand for the way he handled the All Blacks' World Cup quarter-final defeat to France at the Millennium Stadium.
Barnes missed a forward pass in the build-up to a try by Frederic Michalak and his performance was cited as one of the key factors in New Zealand's defeat in an independent review.
All Blacks lock Ali Williams, attempting to defended Henry from the criticism he has received since being re-appointed as head coach, plunged the knife into Barnes again.
He said: "Some of the ownership has got to fall on us too as players, we didn't score the points. You have to look at the ref, 17 unawarded penalties - that's bull."
England's elite rugby director Rob Andrew believes the Currie Cup trials are essentially unworkable, questioning how far back in the build-up to a try the referee can go.