The purposes of this study are to use the residential land transfer data in 42 cities in China to analyze the impact mechanism of the centralized land supply policy on the residential land prices and premium rates based on affiliated value model. The research methods include multi-period differences-in-differences, mediating effect model and moderating effect model. The research results show that the first two rounds of centralized land supply significantly increased the land prices, and the first and the third rounds of centralized land supply significantly increased the premium rates. There is a private value channel where the first two rounds of centralized land supply “screened” joint bidders with stronger funds to participate in the bidding and increased the land transfer price. There is also a market information channel which stabilizes the expectation of housing market and the land transfer price. In conclusion, the policy changes the rhythm of supply and demand, the competition pattern of land sales and the market expectations in the short term, resulting in fluctuations in land prices and premium rates. It is necessary to improve the structure of land supply and adjust the land transfer rules to realize a long-term residential land supply mechanism..