The invention discloses a sliding mode thought-based novel low-pass filter design method. The method comprises the steps of constructing a virtual filtration controlled object according to a first-order inertial link transfer function; for the virtual filtration controlled object, designing a simple sliding mode controller; performing discretization processing on a sliding mode control differential equation set to obtain a discretized expression form of a filter; and inputting a signal, and by selecting proper filtration parameters and observing an output curve, determining final low-pass filter parameters, thereby enabling the whole low-pass filter to have a satisfied low-pass characteristic. The method has the beneficial effects that the nonlinear sliding mode-based nonlinear digital filter has the advantages of sliding mode control, good interference resistance and quick response, so that the filter has small distortion; and the filter has relatively strong noise suppression energy.