You can't. Under normal circumstances, most people choose mortgage loans to buy a house, that is, pay part of the down payment and the rest through bank loans. You can apply for a mortgage or other kinds of loans first. Then take the loan money as a down payment and then go to the loan. But these are two contracts, not one. In other words, borrow money in other ways first and get the money. Then go to mortgage. The down payment must be paid in cash before you can apply for a loan. As for the source of the down payment, it doesn't matter whether it is a loan, a loan or your own money, but the down payment can't be used for a house loan. You can use other tangible assets to borrow money, so that you can pay the down payment, and the rest can be repaid monthly in the form of loans. These are two contracts, but then you have to face mortgage and down payment, which will make your life very stressful.

Legal objectivity:

Article 5 of the Notice on Opinions on Adjusting Housing Supply Structure to Moderately Stabilize Housing Prices has made differential adjustments to the housing consumption credit policy. In order to curb the excessive rise of housing prices, the down payment ratio of individual housing mortgage loans shall not be less than 30% from June 2006 1. Considering the housing needs of low-and middle-income people, the down payment ratio of 20% will still be implemented for those who buy self-occupied houses below 90 square meters.