Zheng Kai graduated from Acting Department of Shanghai Theatre Academy. He cooperated with world-famous directors such as Zhang Yimou and Feng Xiaogang, and was known for The Shadow (2018), The Great Wall (2016), Personal Tailor (2013), Ex-Files series films, etc. Among them, Ex-Files 3: The Return of The Exes has become the highest-grossed romance film in China with a record-breaking RMB 1.9 billion box office. He also starred in TV series such as Rules Before A Divorce (2012) and Big National Life (2017), which generated new audience highs repeatedly. Zheng Kai successively won the honorary titles of “Focus Actor Award of Chinese Movie” at the Fourth Beijing International Film Festival, "Annual Expressive Opera/Star" at the Second Quality Festival of Television Drama, "Golden Knight Prize of Organizing Committee" at the Fifth China-UK Film Festival, and so on. In 2018, as one of the main casts of Zhang Yimou’s film Shadow, he attended Venice International Film Festival and Toronto International Film Festival. His performance in the film was wildly praised both in China and in foreign countries.

In 2014, Zheng Kai joined the national variety show Running Man, for which he won the laudatory title of "National Little Cheetah" with his handsome image and superb sports cells, and became a popular idol in China. During these years, Zheng Kai was featured on the cover of magazines such as Esquire, Men’s Uno, L’Officiel, BAZAAR Men's Style for several times. In 2018, Emporio Armani has officially announced Zheng Kai as the Digital Capsule Ambassador of the brand, which marks his commercial values being recognized on the global scale.