The invention belongs to the technical field of preparation of environment protection materials, and provides a CeVO4-La2O3@HNTs composite photocatalyst, and a preparation method and a use thereof. The preparation method comprises the following steps: 1, preparing a La2O3 photocatalyst: adding different masses of urea to a lanthanum nitrate solution having a certain concentration, carrying out water bath heating stirring, and carrying out high temperature calcination on a product obtained after a hydrothermal reaction in order to obtain a lanthana precursor; and 2, preparing the CeVO4-La2O3@HNTs composite photocatalyst: adding halloysite to a nitric acid solution used as a solvent and adding the lanthana precursor prepared in step 1 to a sodium hydroxide solution used as a solvent during the synthesis of cerium vanadate, adjusting the pH value of the above obtained mixed solution during stirring, pouring the adjusted solution into a vacuum reaction kettle, carrying out a hydrothermal reaction, naturally cooling the obtained reaction product, washing the cooled product, and drying the washed product in an oven to obtain the CeVO4-La2O3@HNTs composite photocatalyst used for degrading tetracycline in antibiotic wastewater. The preparation method is simple, does not cause resource wastes or secondary pollution, and is a green, environmentally-friendly and highly-efficient pollution treatment technology.