In this work, we first report a fast, facile hydrothermal method to synthesize delafossite CuFeO2 crystals through low-temperature (100-160 °C). In detail, CuFeO2 crystals with submicron-sized (100-300 nm) could be obtained based on hydrothermal reaction from the starting materials of Cu(NO3)2, FeCl2 and NaOH at 100 °C for 12h. Furthermore, the TG curve of CuFeO2 is similar to other copper based delafossite oxides, and the CuFeO2 crystals tend to be oxidized by O2 in air at a higher sintering temperature (> 400°C). The obtained CuFeO2 film has an optical transmission of 50-60% in the visible range, and the optical bandgap for the direct band transition was estimated to be 3.18 eV. Finally, the magnetic hysteresis loops measured at room temperature show CuFeO2 crystals exhibit antiferromagnetic behavior, the Néel temperature (TN) about 11 K and the biggest magnetic susceptibility around 0.168 emu g-1. This quick and facile method maybe opens a new route for the preparation of CuFeO2 crystals, due to the low reaction temperature and short reaction time.