Head coach Simon Woolford has added the 45-year-old ex-New Zealand second-row to his staff at John Smith’s Stadium.
Since retiring as a player, when he won the 2004 Grand Final with Leeds, Poching has worked as an assistant at Rhinos, Warrington Wolves, Hull KR and, latterly, Salford Red Devils.
“We have been looking around for some help for a few weeks now,” said Woolford, who has former Wakefield full-back Scott Grix coming in as one of his other assistants alongside Giants legend Luke Robinson.
“Willie was keen to get back into the game after a short break and I think we’ll both be a good fit for each other.
“He brings a lot of UK Super League experience to the table which will be valuable for us all here and is keen to get the boots back on and get onto the paddock which I always like to see.
"He’s relatively local too which is a boost as it’s important to know the local clubs and contacts and he’ll work on a part-time basis initially helping me, Robbo and Grixy and he’s keen to make his mark.
"We’ve probably still got one more support staff member to tie up ahead of the season’s start which we’re close to finalising and then the team will be complete.”
Previous assistant coach Chris Thorman parted company with the club in December.
Poching first arrived in the UK as a player with Wakefield in 1999 before joining Leeds at the end of 2001.
His son Kobe is in the Giants academy system and Poching said: “It’s a good opportunity locally for me to get back into Super League and work at Huddersfield.
"From the outside it looks like a great time to join up under Simon’s new team.”