Cheon is known for work protecting cultural heritage sites and environmental preservation.

[2] He also served as the Executive Director of the Roh Moo-hyun and Kim Dae-Jung Citizen Remembrance Committee in 2009.

From 2011, he began working as the planning adviser and personal assistant to Mayor of Seoul, Park Won-soon.

[3] He joined the Democratic Party of Korea in February 2016 and was nominated as the party's candidate for the Gangbuk A constituency in the 2016 South Korean legislative election but lost to Cheong Yang-seog.

[4] He ran for the same constituency in the 2020 South Korean legislative election and defeated Cheong Yang-seog.