Provided are a method and device for preventing the application in an operating system from being uninstalled. The method includes monitoring the operation which creates log contents in a log system of the operating system; determining whether the operation is to uninstall the application based on the log contents; displaying a prompt whether it is agreed to uninstall the application, if the operation is to uninstall the application. Therefore, the method may prevent the malicious software from uninstalling maliciously, enhancing the security of the intelligent terminal.