I don't have an ID card to stay in a hotel. Can I use a hukou book?

yes.

For minors under the age of 18, the household registration could have been used as a valid certificate to check in.

according to article 6 of the measures for the administration of public security in the hotel industry, "hotels must register when they receive passengers. At the time of registration, the passenger's identity documents shall be checked and truthfully registered according to the prescribed items. If you receive accommodation from overseas passengers, you should also submit an accommodation registration form to the local public security organ within 24 hours. "

the valid identity documents of China citizens (including China citizens who are residents of Hong Kong, Macao and Taiwan) mainly include: household registration book of Chinese people, resident identity card, temporary resident identity card, passport, seaman's card, Chinese people's pass to and from Hong Kong and Macao, and pass to and from Hong Kong and Macao Special Administrative Regions on business;

military officer's card, police officer's card, civilian cadre's card, soldier's card, student's card issued by China People's Liberation Army and Chinese People's Armed Police Force, Hong Kong and Macao residents' travel permit to and from the Mainland, and travel permit for mainland travel permit for taiwan residents and China.

China citizens can register in hotels and restaurants with the above valid identity documents.

Extended information:

According to Article 56 of the Law of the People's Republic of China on Public Security Administration Punishment, "? Hotel workers who fail to register the names, types and numbers of identity documents of the staying passengers as required, or who knowingly bring dangerous substances into the hotel and fail to stop them, shall be fined from 2 yuan to 5 yuan.

hotel workers who knowingly fail to report to the public security organs that the guests are criminal suspects or wanted by the public security organs shall be fined from 2 yuan to 5 yuan; If the circumstances are serious, they shall be detained for less than 5 days and may be fined less than 5 yuan. "

References:

Baidu Encyclopedia-Chinese People's Law on Public Security Administration Punishment

Baidu Encyclopedia-Measures for Public Security Administration in Hotel Industry.