The F&F double-layer oil tank (full name: fiberglass reinforced plastic double-layer oil tank) has both inner and outer layer structures made of fiberglass materials. The "inner shell" in contact with the oil includes multiple layers: an electrostatic conductive layer, an anti-corrosion layer, an anti-seepage layer, and a structural layer. The "outer shell" in contact with the soil includes a structural layer and an anti-corrosion layer. Between the "inner shell" and the "outer shell" is an intermediate testing layer. The entire oil tank is manufactured using a composite process of spraying and winding.