The invention provides a preparation method of particle spherical lanthanum titanate. The method comprises the following steps: under a stirring condition, adding 10 to 20 parts of a lanthanum source-water mixed solution into 40 to 50 parts of a titanium source-alcohol mixed solution; adding sodium hydroxide into the solution and magnetically stirring for 20min to 30min; then transferring a mixture into a reaction kettle and raising the temperature to 180 DEG C to 220 DEG C; reacting for 3h to 48h; standing to room temperature; after removing supernatant, adding a sediment part into a reactor containing 100 parts of a hydrochloric acid solution; after stirring for 20min to 30min, washing with water; centrifugally separating; drying at 60 DEG C to 100 DEG C to obtain white powder, namely the particle spherical lanthanum titanate. The method provided by the invention has the advantages of simple process, low cost, uniform components and a novel shape.