To obtain materials capable of efficiently separating acetylene (C₂H₂) from carbon dioxide (CO₂) and ethylene (C₂H₄), In this work, based on the pore space partition strategy, a pacs-metal-organic framework (MOF): (NH₂Me₂)₂[Fe₃(μ₃-O)(bdc)₃][In(FA)₃Cl₃] (Fe-FAIn-bdc) was synthesized successfully by using the metal-formate complex [In(FA)₃Cl₃]^3- as the pore partition units, where bdc^2-=terephthalate, FA^-=formate. Owing to the pore partition effect of this metal-organic building block, fruitful confined spaces are formed in the network of Fe-FAIn-bdc, endowing this MOF with superior separation performance of acetylene and carbon dioxide. According to the adsorption test, this MOF exhibited a high adsorption capacity for C₂H₂ (50.79 cm³·g^-1) at 298 K and 100 kPa, which was much higher than that for CO₂ (29.99 cm³·g^-1) and C₂H₄ (30.94 cm³·g^-1) under the same conditions. Ideal adsorbed solution theory (IAST) calculations demonstrate that the adsorption selectivity of Fe-FAIn-bdc for the mixture of C₂H₂/CO₂ and C₂H₂/C₂H₄ in a volume ratio of 50∶50 was 3.08 and 3.65, respectively, which was higher than some reported MOFs such as NUM-11 and SNNU-18.