Improving the structural integrity of charge is of great significance for ensuring the working stability of solid rocket motor (SRM). Multi-angle tensile loading tests were carried out on the HTPB propellant bonded specimens. During the tensile process, binocular cameras combined with three-dimensional digital image correlation (DIC) methods were used to analyze the deformation field of the bonded specimens. According to the mesoscopic structure of the specimen, a mesoscopic cohesive zone model (CZM) was established and further subjected to numerical simulation analysis, based on three types of damage modes including particle dewetting, matrix fracture and debonding of the bonding interface. The damage evolution law, cracking mechanism and failure mode of the specimen under different tensile and shear stress states were explored. The test results show that the bonded specimen are more prone to damage under the tensile-shear mixed stress state. At the same time, the bearing capacity of the specimen decreases and a greater tensile displacement will occur with increasing the tensile angle. The area where the strain of the bonded specimen is relatively large at the critical state is the location where macroscopic cracks initiate. The numerical simulation results show that the first principal stress is the main factor affecting the generation of cracks in solid propellants, and when the value of the first principal stress is greater than 0.548 MPa, it will lead to the initiation of cracks. Furthermore, the smaller the stretching angle is, the easier the deweeting between the particle and matrix in the propellant is to occur. However, it is easier for the propellant/liner interface to de-bond and the crack propagation location is closer to this interface when the stretching angle increases.