The Toon Army have endured a torrid campaign this season and sit just two points above the relegation zone as they host Harry Redknapp's struggling Hoops.
"It's going to be one of those days we must win," Pardew told the Shields Gazette.
"Usually, reporters say it's a must-win game – I'm telling you it's must-win. That's what we need to do."
|15/2||Newcastle are 15/2 with William Hill to come from behind to beat QPR
"Even at Fulham [a 2-1 defeat on December 10], I said it wasn't important – it's gone. There's nothing you can do about it. It's the next game – that's the only thing that you can legislate for.
"Already, I'm looking forward to it and it can't come soon enough."
Pardew urged the home support to get behind the team on Saturday, acknowledging that the onus is on them as favourites to get a result.
"We're going to have a lot of pressure this week," the Newcastle boss added. "QPR will be expected to lose, so they can come and play with a little bit of freedom.
"Not us; we're going to have to play under monster pressure. It needs to be full up. They need to be right on our side, whatever happens – even if QPR go 2-0 up."