A wireless earphone with a built-in mobile communications module and a dial-up method of the same are proposed. The mobile communications module is used to automatically answer an incoming call. A wireless electronic dial-up device is used for dial-up communications. The wireless earphone comprises a mobile communications module, a digital signal processor, an earphone, a microphone and a wireless communications module. The mobile communications module is used to receive a first remote signal and emit a first reply modulation signal. The digital signal processor is connected to the mobile communications module and used for processing digital signals. The earphone is connected to the digital signal processor. The microphone is connected to the digital signal processor. The wireless communications module is also connected to the digital signal processor, and is used to receive a second remote signal and emit a second reply modulation signal.