What grade does a 170-room hotel belong to?

Mid-range hotel.

According to the "National Star Hotel Rating Standards of the People's Republic of China", hotels are divided into five standards from one star to five stars. The hotel with 170 rooms is a mid-range hotel with three stars.

Hotels, also known as hostels and guesthouses, are commercial institutions that provide safety, comfort, and allow users to get short-term rest or sleeping space.