The invention discloses a pollution-resistant polyamide composite membrane which comprises a nonwoven fabric layer, a porous support layer, a polyamide layer and a pollution-resistant layer which are stacked sequentially, wherein the pollution-resistant layer comprises a polymer compounding inorganic nano particles; the inorganic nano particles are modified or unmodified inorganic nano particles, and preferably are at least one kind of the nano particles of silver, silver compound, modified silver, modified silver compound, copper, copper compound, modified copper, modified copper compound, zinc, zinc compound, modified zinc, modified zinc compound, titanium, titanium compound, modified titanium and modified titanium compound. The invention also provides a preparation method of the pollution-resistant polyamide composite membrane and an application of the pollution-resistant polyamide composite membrane in the field of liquid separation.