Utilizing the existing methods of legacy-to-cloud migration, considering the special requirements on the stability, real-time, high concurrency, and security aspects of land and resources online trading system, this study proposed a solution to maintain the above characteristics after the migration. The solution is adapted to the cloud from data exchange between internal and external networks, transaction engine, data exchange mode of Browser/Server, and so on. Finally, the test and run are formally carried out in Chongqing, Jiangxi, and other places. This method can also be used as a reference for the legacy-to-cloud migration in public security, urban planning, and other departments.