The invention discloses a method for preparing pentaerythritol stearate from hydrogenated oil.The method includes the following steps that S1, a sodium hydroxide solution is added to hydrogenated palm oil, microwave processing is conducted, a reaction is conducted under stirring, and saponified matter is obtained; S2, a sulfuric acid solution is added to the saponified matter till the pH value is 1 to 2, the material is transferred into a distillation tower, and stearic acid is obtained after distillation is completed; S3, stearic acid, pentaerythritol and a catalyst are put, the material is heated, negative pressure is controlled, and a reaction is conducted; S4, then the vacuum degree is increased to 0.07-0.09 mpa, the material is heated to 155-165 DEG C, and a reaction is conducted for 130-150 min under heat preservation at constant pressure; S5, cooling is conducted after an esterification condensation reaction is completed, kieselguhr is added for decoloration and deordorization, the material enters a plate-and-frame filter press, filter cakes are removed, filtrate is taken and subjected to powder spraying, bead spraying and slicing, and packaging and storage are conducted.The method is stable, reliable, high in yield and capable of achieving industrial production, and the prepared pentaerythrityl tetrastearate product is good in whiteness, low in acid value and high in purity.