The invention discloses a novel LCL filter and a design method therefor, and belongs to the design field of a passive filter. Capacitance and inductance parameters are selected firstly according to a conventional LCL filter design method; next, a fractional order LCL filter circuit is designed; a transfer function and resonant frequency of an output current to an input voltage are obtained through the fractional order LCL filter circuit; and finally, the novel LCL filter is obtained by selecting an inductance order alpha and a capacitance order beta of the fractional order LCL filter. The fractional order LCL filter obtained by adopting the modeling method of the fractional order device is better in filtering effect; by virtue of the addition of the fractional order number, the design of the filter can be more flexible; and in addition, a guiding significance for more widely applying more fractional order devices to the filter is played in the future.