After receiving an associate degree in visual arts from the City University of Hong Kong, Lee briefly worked as a model for the magazine Weekend Weekly (新假期) and starred in a few television commercials. In 2008, Lee signed with Cable TV Hong Kong and began hosting numerous television programs for the cable broadcaster, including entertainment shows, travelogues, and sports programs. She made her acting debut in 2011 for the miniseries ICAC Investigators 2011, portraying the ICAC officer Ashley.

Upon her contract expiration with Cable, Lee joined TVB in late 2012 and appeared in FIFA Confederations Cup 2013 – Kick-Off Carnival. She made a cameo appearance in the 2014 romantic comedy drama Outbound Love; she appeared in seven more TVB television drama serials that same year, playing minor roles.

Lee began to receive attention for her acting after starring as one of the villains in the 2014 TVB anniversary drama, Overachievers. In 2015, she received a TVB Anniversary Award for Most Improved Female Artiste nomination for her performances in Raising the Bar, My “Spiritual” Ex-Lover, and Rear Mirror. In late 2015, Lee was cast in Law dis-Order as the female lead, starring opposite Alex Fong and Liu Kai-chi. She was cast to replace Tavia Yeung, who did not renew her contract, in the drama series The Provocateur. Lee played Vincy Kei in Fashion War, earning critical praise for her performance as the headstrong socialite in a power struggle with editor-in-chief Ip Long (played by Moses Chan). In 2016, she gained recognition as an actress by winning both Star Hub Most Improved TVB Artiste and the TVB Anniversary Award for Most Improved Female Artiste.

In 2017, Lee portrayed the flirtatious Never Wong in the drama series Legal Mavericks, once again earning critical praise for her performance. She was awarded My Favourite TVB Actress at the 2017 Starhub Awards. She appeared in the 2017 comedy drama My Ages Apart, playing Paris, an heiress and unpopular actress who wants to find true love. Lee was nominated for the first time Best Actress and My Favourite Female Character at that year’s TVB Anniversary Awards.

In 2018, Lee starred in the family drama Who Wants A Baby?, earning critical praise for her portrayal as Ellen, a new mother struggling to balance her responsibilities. She won Best Actress at the 2018 TVB Awards, becoming the only actress to have won the accolade only two years after being awarded Most Improved Female Artiste. Lee guest starred in the drama Life on the Line as the wife of Mak Sir (played by Joe Ma).

Lee portrayed cardiothoracic surgeon Dr. Kennis Ching in the 2019 medical drama Big White Duel. In June 2019, she was cast in the romantic drama Beauty and the Boss in which she portrays the titular character Amelia. In July 2019, due to her politicized social media posts, Lee was supposedly dropped from four drama series, including the sequels to Legal Mavericks, Big White Duel, and Who Wants a Baby? Lee made her acting comeback in the action drama Death By Zero, in which she portrays a single mother who becomes the assistant of an assassin.

In June 2019, Lee published an article on Weibo and lamented that “sometimes, it’s not the world and the people ’s hearts that are distorted.” (有時候，扭曲了的不是世界、是人心。). In addition, she also posted on Instagram encouraging voter registration. Mainland China netizens misrepresented her for supporting 2019–20 Hong Kong protests and Hong Kong independence. Mainland China netizens attacked Lee on Weibo, and asked Alipay to remove her as the Hong Kong spokesperson of Alipay. Lee responded on Instagram stating that the words of Hong Kong independence had never appeared in her mind or heart. Despite her response, TVB did not cast Lee in any acting projects. Lee was not asked to return to the sequels of Legal Mavericks, Who Wants A Baby?, Big White Duel, in which she plays major roles in. She was also rumoured to be replaced by Priscilla Wong in the drama series Seven Princesses.

Lee published a memoir titled Where The Heart Is in July 2020.

In August 2020, Lee was cast for the upcoming drama AI Lover, in which she portrays an android.