Diesel additive as well as preparation method and use method thereof

The invention discloses a diesel additive as well as a preparation method and a use method thereof. The diesel additive comprises the following components in percentage by weight: 85%-88% of base oil, 10.4%-13.9% of active liquid, 0.6%-0.8% of fatty acid methyl ester, 0.1%-0.2% of polyisobutene and 0.4%-0.6% of triethylene glycol, wherein the base oil comprises 55%-69% of diesel, 20%-25% of isooctyl nitrate, 6%-10% of triethanolamine and 5%-10% of tetrahydrofuran according to weight; a mixture of 85%-88% of kerosene and 12%-15% of pea meal is illuminated and then liquid in the mixture is separated out to serve as the active liquid. The diesel additive can have remarkable diesel-saving and emission-reducing effects, can be used for adjusting the physical and chemical properties of the diesel in only a national standard range to improve the diesel quality, and in addition, can be favorable for alleviating the environmental pollution.