Since graduating from Korea Aerospace University and Presbyterian University and Theological Seminary, he was in church ministry for seven years at Youngdo Church, Somang Presbyterian Church, and Younghwa Church. He was commissioned to Mongologia in 1992 by the Presbyterian Church of Korea (Tonghap) General Assembly where he established the Ulaanbaatar Korean Language Institute and served as its principal. It was later accredited as Ulaanbaatar College where pastor Yoon served as the founding president. He earned his Ph.D in education at Mongolian National University of Education. Ulaanbaatar College became Ulaanbaatar University in 2002, and pastor Yoon continued to serve the first and second term as its founder and president until 2010. In 2007, with over 2,000 matriculated students, the university became financially self-supporting. It also established affiliate primary and secondary schools. Pastor Yoon then stepped down from his position as planned, and transferred the responsibilities to the foundation. In his furlough year he taught as visiting faculty at Fuller School of Intercultural Studies. He served at 100th Anniversary Memorial Church and is now at JIU to support missions and missionaries.