The invention discloses a power amplifying circuit based on an LM3886 chip. According to the specific circuit design, the power amplifying circuit comprises the LM3886 chip, and also comprises first to ninth resistors and first to eighth capacitors, wherein all the resistors and capacitors are connected with the LM3886 chip. The power amplifying circuit also can be superimposed with an operational amplifier NE5532 chip or an AD827 chip to form a linear pre-amplifying circuit or a tone amplifying circuit. The power amplifying circuit with such a circuit design has the advantages of high output power, low distortion degree, complete protection functions, less exterior elements, easy manufacturing and debugging, and stable and reliable work. The power amplifying circuit is simple and applicable.