How to judge the quality grade of dry hanging stone surface. The quality evaluation includes: water absorption, density, compression resistance, folding resistance, wear resistance, cold resistance, hardness, chemical composition, etc. When selecting, each surface must be examined for defects such as cracks, edges, missing corners, chromatic aberrations, swatch marks, etc. Size, flatness, width, and specular brightness reflect the importance of product quality and are also important for natural grading. The water absorption of dry hanging stone is often a concern of buyers. Pour one-third of a glass of water on the stone surface, and the water will be absorbed in a few seconds, while the dry hanging stone surface in front has a higher water absorption rate. If the dry hanging stone surface is of poor quality, it will be permeated by water. Dry hanging stone has clear surface texture, natural color, thick and connotative. This mode needs to avoid repetition so that the effect is natural. If there are few patterns, there will be obvious repetitions throughout the paving, and the effect will be compromised. In addition, pay attention to the overall color selection. Whether it is warm, light or cool, the real effect can be achieved by comparing it with the texture to achieve the dosage of dry hanging stone preservatives related to the effect and other important indicators. Due to the huge difference in the internal structure of dry hanging stone, the size of the micropores and the water absorption rate are also different. When determining the dosage of a preservative, it should not be underestimated. If the quantity is small, the maintenance effect is not fully expressed; too many consume time and material resources. It is easy to form yellow dirt on the surface of dry hanging stone, which is not aesthetically pleasing. We must test dry-hung stone samples to determine the dosage. A good amount is determined by the penetrating of the preservative to the surface of the stone until it is saturated. For treated water, the appearance should be microporous with the addition of a preservative; for equipment that has been put into use without maintenance, it can be updated and protected. With the development of the natural dry hanging stone processing industry, dry hanging stone has been recognized by more and more people, and the number of dry hanging stones used in daily life has also gradually increased. Dry hanging stone is covered with small holes and can cause illness in case of water, and needs to be repaired before construction.