The zeolitic imidazolate framework-8 (ZIF-8), as a kind of MOF, is widely used in sensors, gas storage/separation, drug delivery, and catalysis due to its adjustable porous structure, high surface area, and excellent chemistry tunability. ZIF-8 is constructed by Zn2+ and 2-methylimidazole and synthesized in the methanol solution. In this paper, we explored the influence of the reused methanol solution for the structure and properties of the synthesized ZIF-8. The as-synthesized ZIF-8 was characterized by an X-ray diffraction instrument (XRD), a scanning electron microscope (SEM), a specific surface area analyzer (BET), and Fourier transform infrared spectroscopy (FT-IR). The results show that the reused methanol solution does not change the phase, porous structure, and BET surface area of ZIF-8. However, the particle size of ZIF-8 increases from 50 nm to 5 um and the productive rate decreases to 7.4% when the methanol solution is reused four times. This work provides new insight into the reuse of dissolvents for the synthesis of MOFs.