Do I need to go to the real estate bureau for filing when buying a second-hand house?

No need. Second-hand housing is generally not the registration certificate of sales contract, because the house sold by the landlord is a house that has been filed with the Housing Authority. So when you sell it to others, you don't have to file it. It has been registered in the system of the Housing Authority. Article 36 of People's Republic of China (PRC) Urban Real Estate Management Law: When transferring or mortgaging real estate, the parties concerned shall register the ownership in accordance with the provisions of Chapter V of this Law. Article 62 When a real estate is mortgaged, it shall be registered with the department designated by the local people's government at or above the county level. Where the land use right and house ownership are obtained due to the disposal of mortgaged real estate, the transfer registration shall be handled in accordance with the provisions of this chapter.