Peng began his career when he was cast as in Tomorrow by director Yang Daqing during a summer vacation in Taiwan. The drama is adapted from the Japanese manga series Asunaro Hakusho, written by Fumi Saimon.^[2] Peng built a teenage fan following after the romantic comedy gained popularity.^[3] In 2003, he took on his first leading role in the Taiwanese drama Scent of Love, which tells the story of two star-crossed lovers who transcend life and death to find one another in their many reincarnations.^{[citation needed]}

In 2005, he starred in the idol drama When Dolphin Met Cat, portraying an autistic youth. To prepare himself for the filming, Peng took one month to learn how to interact with dolphins from a trained instructor.^[4] He then starred in Chinese xianxia drama Chinese Paladin and wuxia drama The Young Warriors, which were extremely popular during their run and led to increased recognition for him in the Mainland.^[5]

Thereafter, Peng made his big screen debut in the movie Exit No.6 (2006), directed by Yu-Hsien Lin.^{[citation needed]} The film put him on the radar of many film directors, including Tsui Hark who cast him in his 2008 romantic comedy, All About Women.^[3] In 2007, Peng was nominated as Best New Actor at the 44th Golden Horse Film Festival and Awards for his performance in My DNA Says I Love You.^[6]