<p>Intermittent rockbursts are prevalent geological hazards in deep underground tunnel projects located in regions of high ground stress. Research on the occurrence mechanism and acoustic evolution characteristics of intermittent rockbursts has important academic value and engineering significance for the prevention, control, prediction and early warning of this type of disaster. In this study, which utilized a true-triaxial rockburst testing system, experiments were conducted on large-scale rock samples with cavities to simulate intermittent rockbursts under true-triaxial conditions. Based on the experimental results, the failure processes and stress characteristics of self-initiated and disturbance-triggered intermittent rockbursts were analyzed in depth. The AE characteristics and failure precursors of intermittent rockbursts were comprehensively explored. In addition, the mechanism and main influencing factors of intermittent rockbursts were discussed by a comparative analysis of actual engineering phenomenon and laboratory test results of intermittent rockbursts. The results show that: (1) the entire intermittent rockburst process can be divided into two phases: initial rockbursts and secondary rockbursts. The evolution of the initial rockburst in the surrounding rock progresses through five stages: microscale failure, particle ejection, splitting into plates, plate bending and bulging, plate breaking and ejection. However, secondary rockbursts may directly split into plates or experience plate breaking and ejection without passing through the small particle ejection stage. There is no clear sequentiality between these stages, exhibiting spontaneity and notably greater intensity. The duration of the initial rockburst phase is significantly longer (i.e., approximately 2–5 times longer) than that of the secondary rockburst phase. (2) Based on their location relative to the initial rockburst, secondary rockbursts can be classified into three types: in situ secondary rockbursts, para-position secondary rockbursts, and ortho-position secondary rockbursts. Among these, the main form is in situ secondary rockburst, which is more likely to occur. In situ secondary rockbursts tend to occur earlier and may persist throughout the phase, whereas para- and ortho-position secondary rockbursts generally occur later. (3) The two different types of evolution in fracture damage and failure characteristics of initial rockbursts and secondary rockbursts can be effectively revealed by AE signals, which provide precursory information for prediction and early warning. (4) The mechanism behind intermittent rockbursts is profoundly complex and involves a cyclical process in the surrounding rock of "instability failure–rebalance–instability failure". The surrounding rock is sensitive to variations in the principal stress <i>σ</i>₁, followed by its responsiveness to cyclic disturbances. The residual energy within the rock serves as the principal energy source for secondary rockbursts, whereas the externally input energy acts as a trigger.</p>