The invention discloses a diesel fuel additive composition. The diesel fuel additive composition is prepared from the following components in parts by weight: 90 to 99 parts of fatty acid mixture and1 to 10 parts of epoxy modified phenolic resin, wherein the fatty acid mixture is prepared by mixing oleic acid, linoleic acid and/or linolenic acid and tall oil fatty acid according to the weight ratio of (0.5 to 4) to (1.5 to 5) to (3 to 8). The diesel fuel additive composition prepared by the invention has the advantages of good lubricity, low content of saturated fatty acid, low price, simplepreparation process and suitability for various diesel fuel systems.