Are there any hotels and guest houses in Tsinghua University?

Yes! On-campus hotels in Tsinghua University:

Standard room 300 yuan/day, suite 370 yuan/day (can be booked, need a letter of introduction)

C is all suites 1200/ room (no standard room, no reservation for standard room).

Near the Spring Garden Hotel, 240 double rooms /260 triple rooms/room (letter of introduction from the department is required).

The ground floor of the civil air defense guest house on the seventh floor of the south. 25/ bed for double room without air conditioning and 20/ bed for triple room without air conditioning (reservation is not allowed).

Xiu Xiu Chubei Building Guest House 35/ bed, quadruple room.

30 yuan/bed of Science and Technology Industry Building Hotel, each room has 4 beds, sharing the bathroom (basically staying for a long time, no reservation).

There are 4 people in the common room of Zhaolanyuan Service Building, 35 yuan/person, with TV phone and public toilet (rooms cannot be reserved).

/Kloc-Room 3, Building 0/8, 45 yuan/person/day, video phone, public toilet (reservation is not allowed).

The repaired guest house has four rooms with air conditioning 35/ person and non-air conditioning 20/ person, and the newly renovated guest house has four rooms with air conditioning 30/ person.

International student building 160 standard room (can be booked a few days in advance and requires a letter of introduction).

Southwest14th floor (near the southwest gate of Tsinghua University) quadruple room 20 yuan/person/day.

I can't book any guest houses in Tsinghua, so I can only check in on the same day. But a place does not belong to a guest house.