In 2006, william joined Sun Boy’z, a Cantopop boy group created by EEG, together with Steven Cheung and Dennis Mark and started adopting a dance-singer persona. The trio has recorded three albums in 2006 and 2007, but disbanded in 2008.
After the disbandment of his group, william began his solo career. In September 2008, william released his first solo album Will Power, and won the Most Popular Male Newcomer award at the 2008 Hong Kong Jade Solid Gold Best Ten Music Awards Presentation and Best Prospect Award at the RTHK Top 10 Gold Songs Awards. The following year, william released his second solo album Warrior. He also participated in Dragon TV's dance program Let's Shake It.
In 2009, william made his big screen debut in crime thriller Overheard. He was cast in his first lead role in Hi, Fidelity (2011), which was showcased at the 35th Hong Kong International Film Festival.
From 2010 to 2013, william released four more albums, namely Do You Wanna Dance (2010), Heads or Tails (2010), WOW (2011) and Pop It Up (2013).
In 2015, william released his first EP titled Waiting. This is also his first Mandarin album. Waiting was a commercial success and achieved platinum certification in sales. The same year in November, he released his self-composed single "1121".
In 2017, he starred in the historical fantasy drama Lost Love in Times and headlined the war epic film Genghis Khan. He has also been cast as the male lead in upcoming modern romance drama Only Side by Side with You as well as crime action drama Age of Legends.