Eddie Jones's much-changed side completed its warm-up fixtures by scoring four tries without reply in Newcastle, captain Owen Farrell converting them all as he finished with a personal haul of 17 points.
However, while it stretched its winning record against Italy to 26 Tests, England produced a performance of two contrasting halves in its final outing before this year's tournament in Japan.
They led only 9-0 at the break thanks to a hat-trick of Farrell penalties and were fortunate not to concede in defence, Tommaso Benvenuti appearing to get around Jonny May only to drop the ball as he headed for the line.
Farrell failed with a penalty attempt early in the second half but England crossed for its first try not long after the skipper's miss, scrum half Ben Youngs getting over from close range.
Joe Marchant marked his first Test start by crossing in the 53rd minute, the centre, who was picked by Jones for the game despite not being included in the final 31-man party for the Rugby World Cup, slicing through some flimsy tackling to score.
Replacement Ellis Genge benefited from his colleagues in the pack to get his maiden international try when finishing off a powerful maul, Farrell's successful conversion making it 30-0.
The five-eighth was also on target after setting up the final try for team-mate Anthony Watson, who capitalised on a tiring Italy defence to breeze through a huge gap and slide over.
Jones will hope to receive a clean bill of health from those involved before England flies out on Monday (AEST). Its opening Pool C fixture is against Tonga on 22 September.