The invention discloses an all-plastic fuel oil filtering module for a lightweight automobile. The all-plastic fuel oil filtering module comprises a base, a rotary clamping sleeve, a filtering tank, an oil-water separation sensor, a water drain valve, a hand pump, a plunger cavity, an air bleed screw, an oil inlet, an oil outlet, a dust cover, a filter element, a flow guide pipe, a filter element upper end cover, a sealing plate end cover, a first diaphragm valve and a second diaphragm valve; the base is provided with the hand pump, the oil inlet, the oil outlet and the first diaphragm valve, the hand pump is provided with the plunger cavity, the oil inlet is provided with the dust cover, the oil outlet is provided with the second diaphragm valve, and the second diaphragm valve is communicated with the air bleed screw; the sealing plate end cover is arranged in the base, the first diaphragm valve is communicated with an oil outlet hole of the sealing plate end cover; and the filtering tank is fastened to the base through threads, the filter element is installed in the filtering tank, the flow guide pipe is arranged in the filter element, and a filter paper top layer of the filter element and the top end of the flow guide pipe are welded to the filter element upper end cover. Functions are modularized, the structure is compact, the universalization requirement of product design is fully considered, and the repeated development cost of an assembly is reduced.