The invention discloses a capacitor filling material. The capacitor filling material is characterized by being prepared from the raw materials based on parts by weight: 35-40 parts of epoxy resin, 10-20 parts of phenolic resin, 1-2 parts of curing agent 5506, 3-5 parts of zeolite powder, 1-3 parts of organic silicon defoamer, 1-2 parts of diisocyanate, 1-3 parts of glass fiber, 5-7 parts of stearic acid, 1-2 parts of linseed oil and 1-2 parts of alkyl polyglucoside. The formula is simple, and the preparation method is simple and practical; the heat- and cold-resistant performance of the capacitor filling material is improved by modifying the phenolic resin; by a reasonable formula, the elasticity and the stability of the capacitor filling material are improved, no toxicity and no harm aregenerated, and the capacitor filling material is stable to use; and with the addition of the zeolite powder and the glass fiber, the heat- and the cold-resistant performance of the capacitor filling material can be improved.