Lin Gengxin made his screen debut in the 2010 Chinese film ‘The Immemorial Magic’ directed by Shi Yi-Chu. In 2011, he portrayed ‘Yinti’ in the Chinese television series ‘Scarlet Heart’ directed by Lee Kwok-lap. The series received positive reviews from critics and was a commercial success. Gengxin also won several awards, including 2 iQiyi Awards, for his performance in the show. He next appeared in the 2012 Chinese television series ‘Xuan-Yuan Sword: Scar of Sky’ where he played the role of ‘Zhang Lie.’ The series became one of the highest-rated television dramas in China. That same year, he also portrayed ‘Tong Shao Tian’ in the Chinese television series ‘Drama Go! Go! Go!’ directed by Danny Dun. The series aired a total of 30 episodes before going off-air in 2013. He starred as ‘Shatuo Zhong’ in the 2013 Chinese action-adventure fantasy mystery film ‘Young Detective Dee: Rise of the Sea Dragon’ directed by Tsui Hark. The film served as a prequel to the 2010 film ‘Detective Dee and the Mystery of the Phantom Flame’ and was the second film in the ‘Detective Dee series.’
In 2014, he portrayed ‘Lin Yi’ in the Chinese coming-of-age drama film ‘My Old Classmate’ directed by Frant Gwo. The film was a financial success and grossed over US$73 million at the box office. That same year, he also played the role of ‘Chen Zhen’ in the Tsui Hark-directed Chinese-Hong Kong epic action film ‘The Taking of Tiger Mountain.’ The film grossed over US$150 million at the box office. He was next seen in films and television series like ‘Jian Bing Man’ (2015), ‘For a Few Bullets’ (2016), ‘Sword Master’ (2016), ‘The Great Wall’ (2016), ‘Journey to the West: The Demons Strike Back’ (2017), ‘Detective Dee: The Four Heavenly Kings’ (2018), ‘Lost and Love’ (2020), and ‘My Bargain Queen’ (2021). He was last seen playing the role of ‘Lu Jiming’ in the 2022 television series ‘Master of My Own’ directed by Yao Ting Ting.
European mercenaries, Irishman William Garin and Spaniard Pero Tovar, reach China during the reign of the Song dynasty, to find the secret to gunpowder. Their lives are changed when they discover that the Great Wall is built to stop an alien race of monsters called Tao Tei from capturing China.