After dispatching their north London rivals 2-0 in the first leg, the Blues put in another dominant performance away from home and were worthy winners in what was a comfortable night for the European champions.
Spurs had two penalty decisions and a Harry Kane goal ruled out by VAR, but all three decisions were correct and aside from the incidents, the hosts never really had a sniff.
Chelsea began the encounter brightly but it was Spurs who had the clearest early chance early on from a dangerous free kick, with Kane striking a low effort into the wall after a silly foul from Andreas Christensen.
Timo Werner then fluffed a good opportunity for the Blues after a poor defensive clearance from Davinson Sanchez, with his chipped effort flying over the bar.
Lukaku came inches away from giving Chelsea the lead when he fired a powerful effort straight at Pierluigi Gollini.
The Belgian was played in following a sumptuous delivery from Antonio Rudiger but couldn't divert his effort around the Spurs goalkeeper.
It was a lightning start to the match and moments later Lucas Moura did well to break from the halfway line before dragging his effort wide of the post.
Chelsea almost got their lead when Lukaku and Werner combined well in the edge of the box with the Germany international cutting back to Malang Sarr who has his effort deflected wide for a corner.
Antonio Rudiger gave the Blues into a deserved lead shortly after the 15 minute mark and it came after an error from Gollini, who was selected ahead of Hugo Lloris.
Mason Mount whipped the ball into the box and the ball struck the German's back before looping in, with the Italian shot-stopper in no-mans land during the corner.
Chelsea were dominating and looked to build on their lead when Hudson-Odoi had an effort parried for a corner by Gollini.
Pierre-Emile Højbjerg fired Spurs' best chance of the game just wide after Kane's effort from close range rebounded back into him.
And the hosts thought they had a penalty shortly before half-time when Rudiger hauled down Højbjerg as he raced through on goal.
However, a VAR review showed the foul had happened outside the area and after Spurs failed to make the set-piece count the sides went into the break with Chelsea holding a deserved lead.
Ten minutes after the break, Spurs had a second spot-kick ruled out by VAR after Kepa Arrizabalaga was adjudged to have won the ball fairly from Lucas Moura.
Kepa then made a brilliant stop from a powerful Emerson Royal header as the hosts looked to claw a way back into the tie.
Spurs then incredibly had a goal ruled out when Kane was adjudged offside after slotting home what he thought was the equaliser.
But the Blues ultimately were hardly tested in the second half and were worthy victors once again.
Tuchel's men will now face Arsenal or Liverpool in the final at Wembley, with both legs still to be played between the two sides.