The invention discloses a rare earth-based luminescent material containing polyacid building units, a preparation method and application thereof, and belongs to the technical field of preparation and application of organic-inorganic chemical hybrid materials. The specific chemical formula of the rare earth-based luminescent material of the present invention is: [Tb 6 (C 16 h 6 o 9 ) 4 (HCOO) 2 (DMF) 4 (H 2 O) 4 ]·2DMF·9H 2 O, the molecular formula is: C 84 h 94 N 6 o 59 Tb 6 , where C 16 h 6 o 9 is 5‑(3’,4’‑dicarboxyphenoxy)isophthalic acid, and DMF is N,N‑dimethylformamide. The present invention uses DMF solvothermal method to prepare the rare earth-based luminescent material containing multi-acid building units. It is a newly synthesized product. It shows bright grass-green fluorescence under the irradiation of ultraviolet lamps, with uniform and pure color, high brightness, and is located in visible light At the same time, the synthesis process of the present invention is simple, the crystallization degree of the material is high, the shape is regular, the purity and yield of the target product are high, and the present invention can be widely used in various energy-saving lamps, fluorescent imaging, fluorescent sensors, new light sources, etc. Fields and promotion of plant growth, ultraviolet disinfection, medical care and other medical and health fields.