In order to study the development and collapse mechanism of the collapsed soil cave in the urban area, the development and failure process of the soil cave were studied through the establishment of a three-dimensional model test. The surface deformation data during the test and the final failure shape of the soil cave were analyzed. Changes in the stress of the covering soil during the development of the cave was also analyzed through the measurement tests of earth pressure. Based on this experiment, a finite element model for calculating the limit radius of the soil cave was established, and the influence of elastic modulus, Poisson's ratio, cohesion and internal friction angle on the limit radius was analyzed through orthogonal experiments. The results show that: for the developed soil cavity, the earth pressure in the failure area is significantly reduced; when the soil cave is damaged, the settlement velocity of the cave top changes suddenly; the law between the height of the damage inside the soil cave and the diameter of the soil cave is consistent with that proposed by Platts theory. The geometric rules are in good agreement; for soil caves with different burial depths, the damage modes are mainly divided into altar-shaped and straight-tube-shaped collapses.