He first got his start working as an extra on Guillermo del Toro's Pacific Rim. His early onscreen credits include Nikita (2012) and Beauty and the Beast (2014). In 2015, he was a member of the Heroes Reborn stunt team, appearing in three episodes as a stunt double. Also in 2015, he appeared as a series regular in Blood and Water (2015–2016), for which he received ACTRA and Canadian Screen Award nominations in 2017.
In 2016, Liu was cast as the ex-CIA analyst Faaron in the NBC prequel series Taken, based on the film franchise starring Liam Neeson, as well as Jung in the CBC television adaptation of the hit Canadian play Kim's Convenience. Also in 2016, Liu joined the cast of the hit BBC-Space series Orphan Black for its fifth and final season, and was nominated for a Dora Mavor Moore Award in the Outstanding Ensemble category alongside his castmates in the Factory Theatre remount of the play Banana Boys.
Liu was named one of Hello! Magazine's 50 Most Beautiful Canadians and 25 Hottest Bachelors in 2017. The magazine dubbed him a "breakout star", noting that he was "as inspiring as he is handsome".
