Among her musical influences, Hui cites the African pygmies and Japanese gagaku court orchestra. Hui aims "to create a personal music of ethereal beauty, intimate lyricism and raucous violence".
Her commissioned works include the orchestral pieces Between You (1992), Common Ground (1993), Aljira (1995), Inner Voices (1995) and In the Breath of the Night (1999), and the large choral work San Rocco (1991). She has also written a large number of pieces for chamber groups: Changes (1990) for chamber ensemble, Speaking in Tongues (1993) for 15 instruments, Foreign Affairs (1994) for 15 instruments, As I Lie Still (1996) for two pianos and percussion, Lacrymosa (1996) for soprano, B-flat clarinet and piano, From Dusk to Dawn (1997) for chamber ensemble, Rush (1997) for pipa and string quartet, Woman: Songs on poems by Sandra Cisneros (1997) for mezzo-soprano, flute, viola and cello, Bop! (1998) for brass quintet and optional drumset, Dog Days (1999) for amplified chamber ensemble, Come as you are (2000) for pipa and nine instruments, sky so empty (2000-1) for string quartet, and And blue sparks burn (2002) for violin and piano, among others. Other works include Sunrise over Tiananmen Square (1998), the soundtrack for the Oscar-nominated documentary, and a chamber opera, The Cellar Door (2002).
Hui currently resides in Montreal, and is a member of the composition faculty at McGill University. Hui served as member of the composition faculty at Stanford University, California, from 1994 to 2004.