Zheng Deyan was born in 1969 and holds a doctorate in agriculture. He began working in June 1989 and he joined the Communist Party of China in May 1988. Of Chinese Han ethnicity, he hails from Wulian county in Rizhao, Shandong province.

Zheng is currently mayor and deputy Party secretary of Yantai in Shandong province. He is also secretary of the leading Party members group of the Yantai municipal government.