It is of great significance to explore the role of land supervision in the standardization of local land transactions. We document the DID strategy to systematically evaluate how land audits affect the transactions in the land market. The results show that: (1) land audits have restrained the transactions of low price of industrial lands and the high price of commercial and residential lands, raised the unit price of industrial lands transactions, and reduced the price of commercial and residential lands, and these effects would not exist in the public sectors land transactions; (2) the impacts of land audits are more pronounced in State-Owned Enterprises (SOEs) and enterprises with large-scale operations and high capital intensity; (3) audits have overall positive significance, which has increased the total investment of local industrial enterprises and reduced the investment bubble. However, there are no deterrent effects. The conclusions have important implications for our understanding of the loss of lands and resources, supervision, and the standardized construction of the trading market.