Austin - who is out of contract in 18 months - has taken the Premier League by storm, scoring nine goals in his past eight league fixtures after netting a hat-trick in Saturday's come-from-behind 3-2 win at home to West Bromwich Albion.
The 25-year-old's 11 Premier League goals - the most of any English player in the division - has helped steer QPR two points clear of the relegation zone.
And Redknapp is not prepared to sell Austin with potential suitors lurking ahead of the January transfer window.
"If we sold Charlie Austin we might as well go home, you know what I mean," said Redknapp.
"He's here. We need Charlie to keep doing what he's doing and he can't afford to take his foot off the gas. I'm not saying he will do it but there's nothing to stop him going on and having a fantastic season. His target would be around 20 goals now with the way he's going at the moment. It's not impossible.
"He's a goalscorer. He wants to score. He works hard, he's got a great attitude. He isn't a minute's problem. There is no side to him - he ain't lairy and gets on with it. He's a lovely boy who's been to work for a living and is now playing Premier League football.
"Goalscorers find a yard of space. It's a knack - he's in the right place at the right time. If you score 20 goals in the Championship this year you'll score in the Premier League. It's not rocket science, it's that knack that people have got - they've been scoring goals since they were kids."
