Eight uncapped players – Mark Atkinson, Jack Kenningham, Louis Lynagh, Gabriel Oghre, Raffi Quirke, Sam Riley, Bevan Rodd and Ollie Sleightholme – have been selected.
The large group also contains nine players who made their debuts for England in their last batch of fixtures, including Jamie Blamire, Trevor Davison and Alex Dombrandt.
There are also recalls for Ben Youngs, Manu Tuilagi and Joe Marler, as well as England's 10-strong British and Irish Lions contingent.
Despite overlooking the Vunipola brothers, George and Ford, Jones insists the door will remain open for all four players.
"This is an exciting squad made up of experienced players and young guys who did well in the summer and have earned their place again," Jones said on Tuesday.
"We have left out some experienced players but we're really clear the door isn't closed to them, and we're looking forward to seeing them work hard to get back into contention."
England's training camp will run from Sunday 26 until Tuesday 28 and forms part of its preparations for the internationals against Tonga, Australia and South Africa in November.
England's 45-man training squad
Forwards: Jamie Blamire (Newcastle), Callum Chick (Newcastle), Luke Cowan-Dickie (Exeter), Tom Curry (Sale), Trevor Davison (Newcastle), Alex Dombrandt (Harlequins), Alex Dombrandt (Harlequins), Charlie Ewels (Bath), Ellis Genge (Leicester), Joe Heyes (Leicester), Jonny Hill (Exeter), Ted Hill (Worcester), Maro Itoje (Saracens), Jack Kenningham (Harlequins), Courtney Lawes (Northampton), Lewis Ludlam (Northampton), Lewis Ludlow (Gloucester), Joe Marler (Harlequins), George Martin (Leicester), Beno Obano (Bath), Gabriel Oghre (Wasps), Sam Riley (Harlequins), Bevan Rodd (Sale), Sam Simmonds (Exeter), Kyle Sinckler (Bristol), Will Stuart (Bath), Sam Underhill (Bath).
Backs: Mark Atkinson (Gloucester), Owen Farrell (Saracens), George Furbank (Northampton), Ollie Lawrence (Worcester), Louis Lynagh (Harlequins), Max Malins (Saracens), Joe Marchant (Harlequins), Jonny May (Gloucester), Raffi Quirke (Sale), Adam Radwan (Newcastle), Harry Randall (Bristol), Dan Robson (Wasps), Henry Slade (Exeter), Ollie Sleightholme (Northampton), Marcus Smith (Harlequins), Freddie Steward (Leicester), Manu Tuilagi (Sale), Anthony Watson (Bath), Ben Youngs (Leicester).