A Chinese-Australian woman, subjected to a slew of racial abuse on a Sydney bus, pleaded for help from the driver but says no one came to her aid.

Lindsay Li was waiting in Willoughby for the city-bound 273 bus at lunchtime on Wednesday when she says an older woman came up to her, spat on her and struck her with her shopping trolley, before pushing ahead of her to get on to the bus when it pulled up.

When the woman reeled around on the bus and began throwing racist insults at Ms Li, the younger woman pulled out her phone and began filming.

The woman was "screaming in a racial tirade, just calling me every name under the sun", Ms Li, 29, told Fairfax Media.