Abstract: UiO−66−NH₂ is a typical Zr−based metal-organic frameworks (Zr−MOFs) with considerable application prospect in CO₂ adsorption. It is a good filler combined with polyvinylamine (PVAm) to prepare mixed-matrix membranes (MMMs). However, the scaling effect of UiO−66−NH₂ preparation is too obvious to scale it up to more than ten-gram-scale. A series of UiO−66−NH₂ was synthesized by changing the ratio of water-acetic acid. Scanning Electron Microscope (SEM), X−ray Diffraction (XRD), Fourier Transform Infrared (FT-IR) and BET test were used to characterize the samples. Through the analysis of characterization results, a mechanism for water-acetic acid promotion of Zr−MOFs secondary-building-unit (SBU) formation was proposed, which has guided the hundred-gram-scale synthesis of UiO−66−NH₂ particles. Furthermore, these particles were combined with polyvinylamine (PVAm) to prepare UiO−66−NH₂/PVAm MMMs, whose separation performance were tested using simulated flus gas (volume fractions of CO₂ and N₂ are 15% and 85%, separately). Compared with PVAm membranes, the separation performance of MMMs increases. The CO₂ permeance reaches 1 937 GPU and the CO₂/N₂ separation factor reaches 85. The result of the cost estimation shows that the use of MMMs can effectively reduce the cost of carbon capture and it also has application prospects in flus gas carbon capture.