Abstract: The expansion and contraction of clay can lead to the formation of cracks, which can significantly alter its hydraulic and mechanical properties and often cause various engineering geological problems. In this study, the indoor experiments are conducted to investigate the improvement effects of basalt fibers on the cracking resistance of clay. A total of 5 sets of samples are designed to quantitatively analyze the effects of fiber content on clay cracking. The soil is taken from a construction site in the suburbs of Hohhot and analyzed using the digital image processing technology. The final results show that the cracking of the soil samples can be divided into three stages: crack generation stage, crack grid formation stage, and crack width expansion stage. In the soil samples mixed with fibers, the orthogonality between the cracks will change, and more dead end cracks will be generated. Through the researches, it is found that the basalt fibers inhibit the cracking of soil, reducing the width and ratio of cracks. With the increase of the fiber content, the moisture content corresponding to the first cracking of the soil samples decreases.