A USP power amplified trumpet connecting device is disclosed. A digital conversion chip and a power amplifier chip are installed to one USB port for being further connected to a trumpet so as to emit sound directly. Moreover, an output connector can be included. Thus the use of the USP power amplified trumpet connecting device is easy and can be portable easily. Moreover, the output connector can be connected to a trumpet and an earphone. The output connector is an optical fiber output connector which is connected to a decoder or an amplifier with optical fiber input so as to emit sound. The output connector includes a general used output and an optical fiber terminal for being connected to an optical fiber output, an earphone or an trumpet.