This book based on the background of the big data era, provides highly effective and reasonable solutions to the issues related to ensuring the safe operation of smart cities. It mainly introduces the paths and forms for building smart cities and effectively responding to information security challenges. Firstly, it summarizes the basic theories of new smart cities and the upgrading of urban wisdom through big data. Then, it puts forward reasonable suggestions for the construction of smart governments in China under the background of big data. Subsequently, taking District S of Hangzhou City as an example, it carefully analyzes the operation mechanism of the smart urban management system from a collaborative perspective and proposes optimization paths. Finally, it conducts in-depth research on the security information system of smart safe cities and its construction methods. This work has significant promoting significance for effectively ensuring the safe operation of smart cities and flexibly responding to new and complex security threats.