Raducanu sealed her third successive-straight sets win in the South Korean capital and has now won three consecutive matches at a tournament for the first time since her stunning US Open title triumph in 2021.
The 19-year-old will face Estonian top seed Jelena Ostapenko or Andorran teenager Victoria Jimenez Kasintseva for a place in the final.
Raducanu, who fell at the first hurdle in defence of her US Open title last month, has slipped to 77th in the world rankings from a career-high 10th.
But the British number two, who beat Japan's Moyuka Uchijima and Belgium's Yanina Wickmayer earlier this week, has rediscovered some of her best form.
Raducanu made a flying start, twice breaking Linette and comfortably holding her own serve on her way to a 5-1 lead before sealing the first set 6-2 after 35 minutes.
Linette, who lost to Czech Republic teenager Linda Fruhvirtova in the Chennai Open final last week, immediately hit back in the second, winning her opening service game to love.
The 30-year-old Pole then led 40-0 on Raducanu's serve, but the Brit dug deep to save three break points and then dealt her opponent a mighty blow by winning against her serve for the third time in the next game to edge 2-1 ahead.
Raducanu held serve and broke Linette for the fourth time in the match to forge into a 4-1 lead and that quickly became 5-1 when holding to love.
Linette extended the match by edging a deuce game on serve in the next, but Raducanu maintained her dominance by winning another service game to love to wrap up the match in an hour and 16 minutes.