The first-line house prices, which began in 2015, continued to rise and became particularly serious under the expectation of the public. How to stabilize housing prices has become one of the biggest challenges facing the government in the "new normal" period. This paper constructs a dynamic house price model with government control house price, and tries to analyze the causes and corresponding countermeasures of house price rising from a theoretical point of view. This paper proves that there is an unstable equilibrium in the expected price, and even if the price does not have the basis of the rise, the optimistic expectations of house prices or future income will still lead to a continuous rise in house prices from a balanced state. In this case, the government's purchase or provision of down payment policy can not stabilize the price, and even the role may be counterproductive, speed up the fluctuations. This paper presents a kind of house price endogenous discount method, theoretically can prove that the method can eliminate the reasons for the continued rise in house prices, which can be a very good price stability. Finally, it also discusses the specific operation of housing prices in China, and provides a new reference for China's housing policy during the "new normal" period.