The invention discloses a metal organic framework compound as well as a preparation method and application thereof. A chemical formula of the compound is [Sr(BDPO)0.5(H2O)].2H2O. The preparation method comprises the following steps: (1) dissolving strontium salt and a BDPO ligand into a mixed solution of N,N-dimethylacetamide and water, and uniformly stirring; (2) sealing an obtained mixture in a container, heating the mixture to 105 DEG C, keeping the temperature constant for 72 hours, and then cooling to room temperature; (3) exchanging a reaction product obtained in the step (2) with dichloromethane for 48 hours or longer, then activating in vacuum at a temperature of 160 DEG C. The metal organic framework compound and the preparation method thereof have the beneficial effects that firstly, the metal organic framework compound is poisonless and harmless, has good chemical stability and thermal stability, and has very high ethane/methane adsorptive selectivity by introducing a polar functional group to modify an organic ligand, and can be used as a potential adsorbent applied to the field of C2H6/CH4 separating; and secondly, the preparation process is simple, reaction conditions are gentle, and operability is strong.