A method for mass production of rare earth oxide nanoparticles comprises the steps: taking a hexahydrate of rare earth chloride as a reaction precursor, dissolving in a surfactant with sodium bicarbonate, stirring and mixing; then heating, and carrying out solvothermal reaction; after the reaction is completed, centrifuging, washing and drying; and finally, calcining to obtain the rare earth oxidenanoparticles. The gram-grade rare earth oxide nanoparticles are synthesized by the solvothermal method, and the method can be used for mass production of the rare earth oxide nanoparticles, has theadvantages of simple operation, low cost, and large-scale production; the nanoparticles have uniform particle size, and can be well applied in the fields of photo-electro-magnetic functional materialsand the like.