Li has now reached three finals at Melbourne Park in the last four years, having lost to Victoria Azarenka last year and Kim Clijsters in 2011. She also lost to Clijsters in the fourth round in 2012.
"Last time was a little bit tough so I will try this time to make one more step," Li said in a courtside interview.
"I think after working with the coach, it's not only about my technique, I'm playing much stronger on court... and more stable from the first point to the second point," she added of her success at the season-opening Grand Slam.
Bouchard was just the second Canadian player of either gender to make it to a Grand Slam semi-final in the Open Era, after Carling Bassett, who was a semi-finalist at the 1984 US Open.
The 19-year-old, however, had trouble from the onset, letting the ball bounce in front of her on the opening serve due to the sun, before her first actual serve was into the wrong service box.
Li wasted little time in bashing three backhand winners in the first game to break the young Canadian to love, held serve, then broke again to love to give her a handy 3-0 lead.
Such was the world number four's dominance, Li did not commit an unforced error until the fourth game and restricted Bouchard to three points in total in the first five.
She continued to force Bouchard back behind the baseline, when rallies extended beyond three shots, but then temporarily lost concentration to allow the Canadian to win two games, before she sealed the first set in 28 minutes with a forehand volley.
Bouchard began the second set with an ace - her first of the match - and while Li held two break points the Canadian appeared to be getting into a rhythm and she battled to hold serve in a game that lasted 11 minutes.
Li's first service game of the second set lasted a further 10 minutes as Bouchard attacked Li's first serve, which had deserted her, with five deuce points before the Chinese belted a forehand out to give the 30th seed a 2-0 lead.
The momentum swung again with Li rattling off three successive games, and six of the final eight, as she continued to be aggressive to set up a final against Dominika Cibulkova, who thrashed fifth seed Agnieszka Radwanska later in the day.
"Tough match of course in the final," Li added of her potential final opponent.
"I think both will fight because it's one more step to take the trophy so we will see."
20-Dominika Cibulkova (Slovakia) beat 5-Agnieszka Radwanska (Poland) 6-1 6-2
4-Li Na (China) beat 30-Eugenie Bouchard (Canada) 6-2 6-4