New signing Marko Grujic marked his first appearance for the club with a goal in the 18th minute, before Jurgen Klopp's side added four more in a dominant second-half performance to cruise to victory at Highbury Stadium.
Liverpool created the first opening of the contest after just four minutes when Jon Flanagan crossed the ball in towards Grujic, but it arrived a bit behind the debutant, who could only send a stooping header well wide.
Grujic was the standout player of the first half, though, and he handed Liverpool a glorious chance to break the deadlock after just 12 minutes when he skipped past Akil Wright inside the penalty area before being tripped by the full-back.
Referee Kevin Friend had no hesitation in pointing to the spot, but Danny Ings, who scored the winner in Liverpool's opening pre-season match against Tranmere Rovers on Friday, saw his tame penalty saved by Fleetwood summer signing Chris Neal.
It wouldn't be long before the visitors broke the deadlock, though, as just five minutes later Grujic got on the end of Alberto Moreno's low cut-back, took a touch and saw his low strike deflect over the diving Fleetwood keeper.
The 20-year-old Serbian midfielder made a number of breaks into the area throughout the opening 45 minutes, and one of them midway through the half saw him strike the post from what looked like an impossible angle.
Liverpool continued to dominate as the first half wore on, and Dejan Lovren was the next to come close when he got on the end of Moreno's cross at the back post, only to see his header turned away by the keeper.
Fleetwood's first meaningful shot of the match did not arrive until the 38th minute, but Jimmy Ryan, who won back-to-back FA Youth Cups with Liverpool, failed to make the most of it as he curled his finish over the top from just outside the area.
The visitors were soon back on the attack, though, and again it was Grujic who threatened with a powerful low strike from the edge of the box that Neal did well to turn away despite it taking a deflection on the way through.
Fleetwood did enjoy a purple patch towards the end of the first half as Liverpool began to get sloppy in defence, but there was no-one at the back post to apply the finishing touch to Amari'i Bell's enticing ball across the face of goal.
Both teams emerged from the interval with completely changed lineups, and it didn't take long for Liverpool's second XI to double their advantage when Ryan Kent squared the ball for 16-year-old Ben Woodburn to sweep home his first goal of the club.
Kent and Woodburn both came close with efforts within one minute of each other shortly before the hour mark, but they were both denied by sub Fleetwood keeper Alex Cairns.
The hosts finally tested the Liverpool keeper for the first time with just under half an hour remaining when Elliot Osborne was played through down the right channel, but his firm strike was straight at Adam Bogdan, who made a comfortable save.
Any hopes of a Fleetwood comeback were soon ended with two Liverpool strikes in the space of as many minutes, though, as first Lucas Leiva got a rare goal by picking out the bottom corner from another Kent cut-back to make it 3-0.
Lucas's compatriot Roberto Firmino added the fourth just a minute later when he fired home a loose ball from the edge of the area after Cairns had smothered Woodburn's initial effort.
Randall and Kent were both denied by Cairns as Liverpool went in search of a fifth, while there was also a rare chance at the other end of the field when Ricardo Kip's header at the far post was kept out by Bogdan.
There was still time for another goal, though, as Firmino capped off the scoring with virtually the last action of the match, tapping home into an unguarded net after being picked out by Woodburn's low cross into the middle.
Liverpool will next take on Wigan Athletic and Huddersfield Town before flying out to the United States to take part in the International Champions Cup.