Is it necessary to isolate from Fugu to Xi 'an?

No need. Xi' an in high-risk areas needs isolation, and low-risk areas don't need isolation. Fugu is a normalized prevention and control area, so Fugu does not need to be isolated when going to Xi 'an. Fugu County is located in the northernmost part of Shaanxi Province, bordering on Qin, Jin and Mongolia, across the river from Hequ County and Baode County of Shanxi Province, bordering Zhungeer Banner and Ejinhoro Banner of Inner Mongolia Autonomous Region in the north and Shenmu City in the southwest. Known as the "three provinces where chickens crow and smell". Xi 'an, referred to as "Gao", was called Chang 'an and Haojing in ancient times. It is the capital of Shaanxi Province, a sub-provincial city, a megacity, the core city of Guanzhong Plain urban agglomeration, and an important central city in western China determined by the State Council.