Which city does tangyin county belong to?

Anyang city. According to official website, tangyin county People's Government is located in the hinterland of the Central Plains, which belongs to Anyang City, Henan Province, with a total area of 636 square kilometers, 10 towns, 298 administrative villages and a population of 530,000. It is a "Millennium Ancient County" named by the United Nations Group of Experts on Geographical Names.