Her mathematical interests include higher category theory, and as a pianist she specialises in lieder and art song.

[5] She is also known for explaining mathematics to non-mathematicians to combat math phobia, often using analogies with food and baking.

[16] Cheng's research interests are in category theory, which she has written about for a general audience by using analogies from baking.

In How to Bake Pi, published on May 5, 2015,[7] each chapter begins with a recipe for a dessert, to illustrate the commonalities in the methods and principles of mathematics and cooking.

[22] Cheng's second book, Beyond Infinity, explains set theory for lay audiences using analogies and anecdotes, including Cantor's diagonal argument and Zeno's paradoxes.

[25] It explores arguments on real-world topics like same-sex marriage, white privilege, and police brutality in the United States using methods from logic, including explanations of Russell's paradox and Euclid's axioms on the way.

[31] She was interviewed by Jim Al-Khalili for The Life Scientific on BBC Radio 4, first broadcast in January 2018.

In a 2024 Wall Street Journal article, Cheng wrote about her fertility issues and childlessness.