Disclosed are an application module startup method and an electronic device. When a first device needs to start an application module that is not installed and that is in an application on the first device or another device that is communicatively connected to the first device, a system module on the first device may query whether the application module is installed on the first device. When it is determined that the application module is not installed on the first device and/or another device, the system module on the first device may communicate with a first server, so that the system module on the first device may download, install, and start a first application module on the first device and/or another device based on a message sent from the first server.