Abstract: Perilous rock in limestone area shows quasi-masonry structure characteristics. It appears disintegration failure phenomenon in the process of collapse. For the discussion on the disintegration of quasi-masonry perilous rock, different bonding ways, depth-width ratio and dip angle of perilous rock were chosen to make 81model tests and to get the earliest cracking location feature in the disintegration of perilous rock by different combination. The results showed that, in the model test, the greater depth-width ratio, the cracking location is closer to the lower of perilous rock and the larger dip angle of controlling structure, the initial cracking location is closer to the upper part. In the meantime, it showed that the bonding mode had little influence to the initial cracking location. In the model test, it studied surface cracking features of perilous rock model when the collapse occurred. The research results provide some scientific basis to disintegration mechanism of perilous rock with quasi-masonry structure characteristics in the Three Gorges Reservoir Area.