In arid climates, red clay has significant fissures, which leads to a large number of engineering geological disasters. In order to inhibit the development of red clay fissures, the influence of palm fiber length and dosage on the development and characteristic indicators of red clay fissures is studied by adding palm fiber to red clay and carrying out indoor dry shrinkage cracking experiments. The results show that in the process of dry cracking, the fracture characteristics of red clay experience a stage from rapid growth to stabilization, but the variation laws are not exactly the same. When the fracture rate tends to be stable, the fracture length gradually increases, while the fracture width shows a gradual decrease trend. The soil surface central fissures occur earlier than the boundary fissure, the intersection angles between the central fissures are about 90°, and the boundary fissures are roughly parallel to the boundary. With the increase of palm fiber dosage, the fracture rate and fracture width of the reinforced soil decrease accordingly, and the fracture length decreases first and then increases. With the increase of the length of the palm fiber, the fracture rate and fracture width of the reinforced soil reduce first and then increase, and the fracture length reduces first and then increases and finally decreases. Palm fiber dosage 0.3%, palm fiber length 10mm and appropriate moisture content can effectively inhibit the development of red clay fissures.