针对硬地层及软硬交错非均质地层中聚晶金刚石复合片（polycrystalline diamond compact, PDC）钻头易损坏、破岩效率低的问题，研究以单齿破岩实验为基础，通过有限元软件，建立了基于INP文件二次开发的非均质砾岩模型，模拟不同后倾角、切削深度和切削轨迹下的破岩过程，分析岩石破碎形态、应力分布及载荷特性，揭示了切削参数及齿形结构对破岩性能的影响机制。结果表明：平面齿的切削效率与切削齿后倾角呈正相关性，后倾角优化至30°时，其破岩效率实现最大化，而斧形齿在20°时效率最高，其效率与后倾角呈非线性关系，切削范围随角度增大而缩小；切削深度为10 mm时，应力值升高，应力影响范围扩大，岩石变形显著，破岩比功最小为5.41 mJ/mm³；斧形齿前端凸起的脊刃部分先与岩石接触形成应力集中区，使岩石更容易发生破碎，且切削轨迹各处的应力值变化幅度较小，整体的切削过程中更加稳定。通过优化后倾角及切削深度实现破岩效率最大化。研究成果为PDC钻头的个性化设计和优化提供了重要的理论依据，尤其对砾岩层钻进具有重要指导意义。

A study was conducted to address the issues of rapid damage and low rock-breaking efficiency of polycrystalline diamond compact (PDC) bits in hard formations and heterogeneous interbedded formations. Through single-cutter rock-breaking experiments and finite element simulations, a heterogeneous conglomerate model was established using INP file secondary development. The rock-breaking process under varying back rake angles, cutting depths, and trajectories was simulated, with analyses focusing on rock fragmentation patterns, stress distribution, and load characteristics. The mechanisms influencing rock-breaking performance were revealed. The results show that planar cutters exhibit a positive correlation between cutting efficiency and back rake angle, achieving maximum efficiency at 30°. In contrast, axe-shaped cutters show peak efficiency at 20° with a nonlinear relationship to back rake angle, accompany by reduced cutting ranges as angles increase. At a cutting depth of 10 mm, stress values increase significantly, stress-affected zones expand, and rock deformation intensifies, yielding the minimum specific rock-breaking energy of 5.41 mJ/mm³. The ridge-like protrusion at the front of axe-shaped cutters initially contacts the rock, forming localized stress concentration zones that facilitate efficient fragmentation. Additionally, stress fluctuations during cutting trajectories remain stable. By optimizing back rake angles and cutting depths, rock-breaking efficiency is maximized. The research results provide critical theoretical guidance for the customized design of PDC bits, particularly for drilling in conglomerate layers and heterogeneous formations.