Patri Guijarro had a late fifth goal ruled out for offside at the Estadio Butarque as Barça made it 13 consecutive Clásico wins since Madrid officially absorbed CD Tacon in 2021.
Madrid turn their attention back to Liga F, where they are nine points behind Barça after 13 games.
They also remain in the Copa de la Reina although they have already been eliminated from the Champions League after collecting just one point in four group games.
Barça, the reigning Spanish and European champions, went into Wednesday’s game as favourites and started quickly to effectively book their place in the final by half-time.
Caldentey, playing as a false nine, opened the scoring from close range in the 12th minute after Madrid failed to clear a corner to set the tone for another dominant display.
The second goal arrived just three minutes later when Paralluelo finished with the outside of her boot after full-back Ona Battle had kept an attack alive.
Barça’s third arrived before the break after VAR intervened and a penalty was awarded for Ivana Andrés foul on Caldentey, who converted her 10th goal of the season from the spot.
Paralluelo took her tally for the campaign to 14 early in the second half after latching on to a fine pass from Caroline Graham Hansen.
Giraldez then withdrew Caldentey and Paralluelo to deny either the chance of a hat-trick as thoughts turned to resting legs ahead of the final.
Guijarro thought she had scored a fifth late on, which would have matched the result from when the teams met in Liga F in November, but the goal was ruled out by VAR for an offside in the build-up.
Barça will now face Levante at the Estadio Butarque this weekend with the chance to win the Supercopa for the third consecutive year and claim what they hope will be the first of four trophies this season.