Yang was born in Jilin province in 1972. She graduated from the People's Liberation Army Academy of Art in 1995, beginning her career as a dancer and theater actress in a PLA drama troupe. She left in the mid-1990s, transitioning into filmmaking with her first documentary, Old Men (1999), which focused on the daily lives of a group of octogenarians in Beijing.
Established filmmakers in the New Documentary Movement at the time, such as Wu Wenguang and Zhang Yuan, typically used studio equipment and multi-person crews to shoot their documentaries. Following their example, Yang initially hired a cameraman and soundman, but, unhappy with their formal style, began shooting Old Men (1999) herself on the Panasonic EZ-1, a MiniDV camcorder. Her techniques and use of the DV (digital video) format's closer point of view impressed Wu, who mentored her and gave feedback on her project. As one of the first Chinese documentarians to adopt the format, Yang helped initiate the DV turn in the New Documentary Movement, "situating [herself] as an emblematic transitional figure". Old Men won multiple festival awards, including the Jury Award at the Cinéma du Réel and the Asian New Current Award at the Yamagata International Documentary Film Festival.
Her first acting role came in Jia Zhangke's Platform (2000), where she played Zhong Ping, a member of a performance troupe dealing with changes following the Cultural Revolution.[9] The same year, her family history and parents' divorce was the subject of her second documentary, Home Video.[10] During this period she went by the stage name "Yang Tianyi".
Yang turned to feature filmmaking in the 2010s, conceiving of a trilogy of women-focused films.[10] It began with Longing for the Rain (2013), which portrayed female sexuality amidst economic and class issues;[10] it was followed by Spring Tide (2019), a family drama about three generations of women and their conflicts, and concluded with Song of Spring (2022), about an elderly woman forced to take care of her daughter who has developed Alzheimer's disease.[11]
Big World (2024), based on screenwriter You Xiaoying's personal experiences, starred Jackson Yee as a young man with cerebral palsy. It won the Audience Award at the 37th Tokyo International Film Festival.[12]
Yang served on the jury of the 27th Shanghai International Film Festival in 2025.[13]