为了研究水中高压电脉冲荷载作用下页岩应力分布和裂纹扩展长度、偏转角度的变化规律,采用应力叠加原理从理论角度探究了水中高压电脉冲作用下的页岩原生和诱导应力场分布规律，结合水中高压电脉冲致裂系统开展了三轴压力作用下的水中高压脉冲破岩及预制裂纹扩展试验，从宏观角度探究了不同预制裂纹长度（10、20 mm）和角度（60°、90°、120°）对裂纹扩展的影响规律；并利用数值模拟软件ABAQUS的扩展有限元模块（Extended Finite Element Method，XFEM）开展了水中高压脉冲破岩及预制裂纹扩展数值模拟计算，进一步从细观角度研究了不同预制裂纹长度和角度对裂纹扩展的影响规律。研究结果表明：在水中高压电脉冲荷载作用下，井筒周边易发生张拉破坏，裂纹在原生地应力场及诱导应力场的共同作用下易出现竞争、偏转等现象；预制裂纹间夹角越大、长度越长，则裂纹的总偏转角度越大、延展长度越长、缝间干扰作用越弱；预制裂纹尖端、裂纹偏转处应力集中现象明显，预制裂纹之间的应力场集中分布于夹角之间区域，并且随着预制裂纹夹角的增大，集中应力区域范围逐渐减小，应力值随之减小，裂纹扩展偏转角度逐渐减小，裂纹间相互干扰程度越来越小。

To study the stress distribution, crack propagation length, and deflection angle of shale under the action of high-pressure electric pulse loads in water, the stress superposition principle was employed to theoretically investigate the distribution of primary and induced stress fields in shale under the influence of high-voltage electric pulses in water. Coupled with a high-voltage electric pulse fracturing system in water, underwater high-voltage pulse rock-breaking and prefabricated crack propagation experiments under triaxial pressure were conducted. The effects of various prefabricated crack lengths (10, 20 mm) and angles (60°, 90°, 120°) on crack propagation were examined from a macroscopic perspective. Numerical simulations of underwater high-voltage pulse rock-breaking and prefabricated crack propagation were performed using the extended finite element method (XFEM) in ABAQUS software. The influence of different prefabricated crack lengths and angles on crack propagation was further analyzed from a microscopic perspective. The research results indicate that: under the action of high-voltage electric pulse loads in water, the surrounding wellbore walls are prone to tensile failure, and cracks are prone to competition, deflection, and other phenomena under the combined action of the original in-situ stress field and induced stress field. The larger the angle and length between prefabricated cracks, the greater the total deflection angle, the longer the extension length, and the weaker the interference between cracks. The stress concentration phenomenon at the tip and deflection of prefabricated cracks is obvious, and the stress field between the prefabricated cracks is concentrated in the region defined by the angles. As the angle between the prefabricated cracks increases, the extent of the concentrated stress region gradually decreases, accompanied by a corresponding reduction in stress values. Consequently, the crack propagation deflection angle decreases, and the mutual interference between cracks diminishes progressively.