<p>The coupling effect of disturbance and unloading during the tunneling process of soft and hard composite rock formations in deep-buried tunnels significantly affects the stability of the surrounding rock, while existing studies inadequately revealed the mechanical behaviors of composite rock bodies under such complex stress paths. This study aimed to investigate the strength deformation and failure behavior of composite rock under complex stress disturbance and unloading conditions. Seven bedding angles of soft and hard interlayer rock-like specimens were configured. A triaxial multi-stage fatigue–unloading–confining pressure test (MFT–MSUCP) was designed which considered the bedding angle and four stress path parameters (including amplitude increment, cycle number, confining pressure, and confining pressure reduction). The test results showed that compared with the multi-stage fatigue test (MFT), MFT–MSUCP showed a significant decrease in both strength and axial strain ranging from 10.05 to 62.86%. The sensitivity of strength to the unloading effect was higher than that of the stress path parameters, especially the cycle number. The fracture patterns of composite rocks under the MFT–MSUCP path were significantly different from that of MFT, mainly in the increase of localized tensile cracks and the diversification of mixed tensile–shear crack combinations. 3D CT reconstruction showed that the fracture volume of the composite rock decreased and then increased with the increase of bedding angle, which were 6.38%, 4.58%, 4.57%, 2.02%, 3.06%, 5.94%, and 5.68%, respectively. Ultimately, based on the seepage simulation, seepage channels in composite rocks could be summarized into three types: tensile fracture channel, facies channel, and mixed channel.</p>