The present invention discloses a palladium-doped lanthanum ferrite powder preparation method, which comprises: selecting raw materials such as lanthanum nitrate, iron nitrate, palladium nitrate, citric acid and polyethylene glycol; and respectively weighing lanthanum nitrate, iron nitrate and palladium nitrate according to a ratio of mol(La)<3+> to mol(Fe)<3+> to mol(Pd)<2+> of 1:(1-x):x, adopting deionized water to respectively dissolve, mixing the obtained three solutions, adding citric acid and polyethylene glycol, uniformly mixing to obtain a transparent sol, evaporating water from the sol to obtain a wet gel, drying the wet gel to obtain precursor dry gel powder, and calcining the precursor dry gel powder to obtain the palladium-doped lanthanum ferrite powder, wherein x is 0.05-0.1, the molar amount of the added citric acid is 1.0-1.5 times the total molar amount of the lanthanum nitrate, the iron nitrate and the palladium nitrate, and the weight of the added polyethylene glycol is 0-0.3 time the weight of the citric acid. The method has advantages of low cost, market prospects, high product sample purity, good uniformity and the like.