Hi, What tourist bus shall I rides from Terracotta warrior site back to west street bell tower.ty

Well, there is no direct public transportation that can take you to the Bell Tower.
But you can take tourist bus line 5 at the Terracotta Warriors, and get off at the railway station. The operating hours are from 08:10 to 19:00 with the duration of around 40 mins.
After arriving, take a taxi to the destination directly. The cab fare is CNY 10 to CNY 15.
Or take a city bus from railway station to Bell Tower; buses traveling between include 251, 611, 706, 603, 707, 201...