Public rental housing is an important governmental project. Within the next three years, Chongqing municipal government proposes building 40×10⁶ m² of public rental housing to solve the housing problem for 2 million people. Many problems of sustainability have happened in long-term large-scale construction, including gradually-slow renting progress, the shortage of funds, public rental housing community facilities are retrograde, and the selected sites are at the city’s edge. This paper analyzes the Chongqing public rental housing situation from the perspective of sustainable public rental housing supply, putting forward a sustainable supply model that is suitable for Chongqing, and then calculates their portion.