The invention relates to a zero-ripple high-gain DC-DC converter based on a novel boost unit, including a low-voltage DC power supply V in , power switch tube S, first power diode D 1 , the second power diode D 2 , the third power diode D 3 , the fourth power diode D S1 , the first coupled inductance L 1 , the second coupled inductance L 2 , the first capacitor C 1 , the second capacitor C 2 , output resistance R o and a DC-DC conversion module; the DC-DC conversion module includes a group of new boost units, i=1,...,N, and each group of new boost units includes an independent inductor L i0 , power diode D i0 ,capacitance C i1 and capacitance C i2 The converter of the present invention not only has the characteristics of zero input current ripple, low voltage stress of power devices, simple control circuit, etc., but also can achieve higher voltage output by expanding a specific number of boost units. In addition, in the case of the same output voltage, the more the number of extended boost units, the lower the voltage stress of the power device.