Where is the three-body combat center?

Ningbo Museum.

According to Douban, the battle center of the first episode of "Three-body" is located in Ningbo Museum, Zhejiang Province, and the physical laboratory is located in BEPC3, the Beijing Electron Positron Collider.

"Three-body" is a sci-fi TV series starring Lin Yongjian, Li and Olivia.