After an inspired performance from Vale goalkeeper Jak Alnwick kept the game goalless at half-time, strikes from Poleon and Tom Elliot, early in the second half set Wimbledon on their way.
And late goals from Tyrone Barnett and Chris Robertson earned a first league win since thrashing Bury 5-1 in November
Vale's defensive concerns remain and they have now won just once in 10 matches.
The home side dominated for much of the first half but Alnwick made four exceptional saves to keep it goalless.
In the 53rd minute the home side broke the deadlock when Sean Kelly made an excellent run down the flank and crossed for Poleon to bundle in from close range.
Elliot headed home from a corner in the 58th minute to make it 2-0.
Soon afterwards Wimbledon keeper James Shea turned Nathan Smith's effort onto the crossbar, before Barnett and Robertson netted in the final five minutes.
Match ends, AFC Wimbledon 4, Port Vale 0.
Second Half ends, AFC Wimbledon 4, Port Vale 0.
Attempt missed. Tyrone Barnett (AFC Wimbledon) right footed shot from the centre of the box misses to the right.
Attempt missed. Andy Barcham (AFC Wimbledon) left footed shot from a difficult angle on the left misses to the right.
Tyrone Barnett (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Kiko (Port Vale).
Goal!  AFC Wimbledon 4, Port Vale 0. Chris Robertson (AFC Wimbledon) header from the left side of the six yard box to the bottom left corner. Assisted by Dean Parrett with a cross.
Corner,  AFC Wimbledon. Conceded by Ryan Taylor.
Attempt blocked. Lyle Taylor (AFC Wimbledon) right footed shot from outside the box is blocked.
Attempt missed. Andy Barcham (AFC Wimbledon) right footed shot from the left side of the box is close, but misses to the right.
Goal!  AFC Wimbledon 3, Port Vale 0. Tyrone Barnett (AFC Wimbledon) left footed shot from the centre of the box to the bottom left corner. Assisted by Lyle Taylor.
Attempt blocked. Quentin Pereira (Port Vale) right footed shot from outside the box is blocked.
Attempt saved. Nathan Smith (Port Vale) header from the centre of the box is saved in the centre of the goal.
Attempt saved. Dean Parrett (AFC Wimbledon) right footed shot from outside the box is saved in the centre of the goal.
Sam Kelly (Port Vale) is shown the yellow card for a bad foul.
Andy Barcham (AFC Wimbledon) wins a free kick in the attacking half.
Foul by Sam Kelly (Port Vale).
Anthony de Freitas (Port Vale) is shown the yellow card for a bad foul.
Tyrone Barnett (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Anthony de Freitas (Port Vale).
Substitution, AFC Wimbledon. Tyrone Barnett replaces Tom Elliott.
Corner,  AFC Wimbledon. Conceded by Nathan Smith.
Substitution, Port Vale. Sam Hart replaces Sebastien Amoros.
Corner,  AFC Wimbledon. Conceded by Kiko.
Lyle Taylor (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Anthony de Freitas (Port Vale).
Substitution, AFC Wimbledon. Andy Barcham replaces Dominic Poleon.
Foul by Tom Elliott (AFC Wimbledon).
Quentin Pereira (Port Vale) wins a free kick in the attacking half.
Kiko (Port Vale) wins a free kick in the attacking half.
Foul by Dean Parrett (AFC Wimbledon).
Attempt saved. Nathan Smith (Port Vale) right footed shot from the centre of the box is saved in the top centre of the goal.
Dean Parrett (AFC Wimbledon) is shown the yellow card for a bad foul.
Foul by Dean Parrett (AFC Wimbledon).
Sam Kelly (Port Vale) wins a free kick in the attacking half.
Attempt missed. Barry Fuller (AFC Wimbledon) right footed shot from the centre of the box is high and wide to the right.
Tom Elliott (AFC Wimbledon) wins a free kick in the attacking half.
Foul by Remie Streete (Port Vale).
Jake Reeves (AFC Wimbledon) wins a free kick in the defensive half.
Foul by Anthony de Freitas (Port Vale).
Report supplied by the Press Association
Dominic Poleon grabbed his 12th goal of the season as AFC Wimbledon thumped Port Vale to earn their first win in four games.