A detachable projection module and an electronic device having the same integrate an optical engine and an image processing unit into an independent detachable module, where the module case is fixedly connected to a device body of the electronic device, so that projection module can receive image signals from the electronic device and convert the received image signals into projection signals to be projected onto a surface near the device body of the electronic device. Through a dedicated or generic connector interface, the detachable projection module may be removed from one electronic device and be mounted to another electronic device, giving an electronic device capability of equipping a projection module to extend the electronic device with a secondary display or empower an electronic device, which has no display at first, with display ability.