In order to simplify the synthesis process and reduce sample loss, propionic acid was used as an additive, through changing the concentration ratio of propionic acid to chromium nitrate nonahydrate, the synthesis of MIL-101(Cr) with micro-mesoporous hierarchical structure was conducted. The particle size, BET specific surface area, pore volume, N2 adsorption properties and microstructure of MIL-101(Cr) with different concentration ratios were investigated by X-ray diffractometer, automatic surface and porosity analyzer and scanning electron microscopy. The results showed that: choosing proper amount of propionic acid could synthesize MIL-101(Cr) with micro-mesoporous hierarchical structure, which had stronger adsorption performance. In this reaction system, the concentration of propionic acid could change the structure of MIL-101(Cr), and the synthesis method was simple and convenient, providing a feasible solution for expanding the application of MIL-101(Cr).