Affordable housing, which is often referred to as affordable housing, is equivalent to a national house; Refers to the social security housing supported by China municipal government with the characteristics of economy and applicability. The so-called economy means that the housing price is moderate relative to the market price in the same period and suitable for the affordability of low-and middle-income families. The so-called applicability means that the building standard of the house cannot be lowered, and a certain use effect must be achieved. Like many other countries, affordable housing is a policy arrangement made by the state to solve the housing problem of low-income people, and another national housing policy based on rental is called low-rent housing.