The invention discloses a pecan raw material complex preservative before storage, an application method and a fresh-keeping pecan. The preservative is prepared from the following components in parts by weight: 3-10 parts of pre-gelatinized starch, 1.2-3.6 parts of an antioxidant, 0.2-1.0 part of calcium chloride, 0.8-1.6 parts of an antibacterial agent, 0.1-0.5 parts of citric acid monohydrate, 0.3-1.2 parts of an emulsifier, and 15-30 parts of an alcohol solution; the antioxidant is prepared from the following components in parts by weight: 0.2-0.8 parts oftert-butyl hydroquinone, 0.4-1.2 parts of a rosemary extract, and 0.6-1.6 parts of a bamboo leaf antioxidant. The preservative adopts the composite antioxidant, can achieve a synergistic promotion effect, can effectively reduce the shortage of the use of a single antioxidant, and achieves a good anti-oxidation effect at the same time; citric acid monohydrate is added to provide an acidic environment for the whole complex preservative and improve the anti-oxidation effect of the antioxidant, and the antibacterial agent can favorably play a greater role.