He is one of the most prolific and highly regarded scriptwriters in Taiwan and a leading member of the New Taiwanese Cinema, although he has also acted in a number of films.

After penning his first screenplay in 1978, Wu entered Central Motion Picture Corporation as a creative supervisor and worked with several leading Taiwanese New Wave directors such as Hou Hsiao-hsien and Edward Yang.

[3] In an interview with film scholar Michael Berry, Wu stated that "I was already working in Taipei at that time, and the extra money I earned from publishing my stories in the newspapers actually added up to more than my salary, which made me very happy and inspired me to keep on writing.

"[4] He started making a name for himself on the Taiwanese literary scene with a series of popular and commercially successful short story collections, including Grab on to Spring (抓住一個春天) (Zhuazhu yige chuntian)(1977).

One of Wu's role models and mentors as a writer was Cheng Ching-wen, who wrote the short story collection Three-Legged Horse.

"[5]Wu's storytelling talents and penchant for realistic dialogue caught the attention of a Taiwanese movie studio named Central Motion Picture Corporation (CMPC), which hired him as a scriptwriter and creative supervisor while he was still finishing his college studies.

[2] Other notable screenplays Wu has written (some of which are considered integral films of the Taiwanese New Wave or New Taiwanese Cinema movement) include Edward Yang's feature directorial debut, That Day, on the Beach (1983), Hou Hsiao-hsien's films The Puppetmaster (1993), A City of Sadness (1989), and Dust in the Wind (1986), and films directed by Anne Hui including Song of Exile (1990) and My American Grandson (1990), and Taiwanese commercial hits Old Mo's Second Spring (1984) and The Dull Ice Flower (1989).

Wu also wrote the screenplay for all the short film segments of the Taiwanese New Wave omnibus film The Sandwich Man (1983) based on stories from the collection by Huang Chunming, with segments directed by Hou Hsiao-hsien, Tseng Chuang-Hsiang and Wan Ren.

太平天國, Taiping Tianguo (1996), a political satire set in the 1960s which was also nominated and in competition for the prestigious Golden Lion at the 1996 Venice Film Festival.

In 2013, Wu played the older mobster character Ho Cheng-Chih in Chien-yu Yu's 2013 (but released 2016) gangster film, Mole of Life.

Wu also appeared as an actor in Buddha Bless America (1996), which he also wrote and directed, and acted in several Taiwanese New Wave films of the 1980s, including Kun Hao Chen's My Favorite Season (1985) and Out of the Blue (1984) and Ko I-chen [zh]'s I Love Mary (1984).