Abstract: To investigate the spalling failure characteristics of deep arch roadway with vertical walls, the three-dimensional unequal pressure loading test was carried out on cubic granite specimens with roadway with vertical walls using TRW-3000 rock true-triaxial electro-hydraulic servo mutagenesis test machine,and the surrounding rock failure of the arch roadway with vertical walls was monitored in real-time using a micro-camera. The results show that the surrounding rock of roadway produced spalling structure parallel to the straight-wall, showing obvious tension failure characteristics. With development of spalling failure to the deep along the sidewalls of the roadways, the symmetrical V-shaped notches were formed at (0.20-0.25)h (h is the height of the arch roadway with vertical walls) from the arch bottom on both sidewalls of the hole. Under the same stress conditions, the initial failure stress of the sidewall of roadway is higher compared with the failure characteristics of the circular hole sidewall of granite,which mainly shows static failure. The rock fragments produced by the failure of the roadway sidewall were larger and slender, showing obvious spalling failure phenomenon. However, the failure of the sidewall of circular roadway is more severe and belongs to dynamic failure. The rock fragments produced by the failure of the circular roadway were relatively small, but the profile of rock fragments produced by the two kinds of sections is thick in the middle and thin on both sidewalls. By comparing the failure characteristics of surrounding rock of roadway with different lithology, it is found that the failure of surrounding rock of granite roadway is more severe, while the failure of that red sandstone roadway is weaker. For the phyllite arch roadway with vertical walls, with increasing bedding angle,the failure mode of surrounding rock changes from tension parallel to the bedding planes to shear sliding parallel to the bedding planes, then transitions to shear failure across the bedding planes, and finally transforms into tensile failure across the bedding planes.