The comparative tests of various properties of the calculus body of calcined ginger nuts before and after ultrafining with quartz sand were carried out. The structure, composition and morphology were analyzed using Fourier transform infrared spectrometry, X-ray diffraction and scanning electron microscopy. The applicability of the ultrafine powder of calcined ginger nuts in the process of reinforcing rock and soil cultural relics is discussed. The results show that, compared with normal calcined ginger nuts, the peaks of SiO₂ in the calculus body of calcined ginger nuts after ultrafining were weakened, and the those of CaCO₃ and Ca₂Al₂SiO₇·nH₂O were enhanced and sharpened, indicating that ultrafining was beneficial to the carbonization of Ca(OH)₂ and the hydration of SiO₂ and β-CaSiO₃. The hydration ratio, condensation time, shrinkage rate, moisture content and wave velocity of the calculus body after ultrafining were improved, and early compressive strength and flexural strength were increased. The water resistance, freeze-thaw resistance, stability and alkaline resistance of the calculus body after ultrafining were significantly improved. The calculus body after ultrafining had better adhesion and compatibility with tuff and red sandstone. In brief, ultrafining has not only retained the advantages of normal calcined ginger nuts but also given full play to the potential cementation properties of calcined ginger nuts. Therefore, the use of calcined ginger nuts after ultrafining is more suitable for the conservation and reinforcement of rock and soil cultural relics.