Based on the 4415 earthquakes body wave arrival times recorded by the 47 fixed and 33 temporary stations in Tangshan and its surrounding areas, the Tangshan fault’s area focal parameters and three-dimensional fine velocity structure model were inversed by using the consistency-constrained double-difference tomography method. The results revealed that the relocated earthquakes were roughly vertical to the fault’s strike, with the maximum depth exceeding 25 km. The Tangshan fault’s area Vp, Vs and Vp/Vs values demonstrate obvious inhomogeneity, and high speed bodies prone to the brittle fault are dominant on both sides of the fault in the upper crust. Small low velocity bodies appeared initially at the Ms7.8 Tangshan earthquake source in the 14–16 km range of the middle crust, followed by a gradual expansion of the low velocity area with an increase in depth. Variation in the velocity structure below the Tangshan earthquake source shows that the high temperature mantle source invading the crust has weakened the upper crust’s high-speed area, leading to stress accumulation in the local area, which is an important factor for the occurrence of earthquakes in the Tangshan region. The relationship between the regional seismic structure and Tangshan seismic sequence, causing migration of surrounding blocks and seismic activity in recent years was analyzed based on the Tangshan fault’s 3D highresolution velocity structure imaging. It is considered that the Tangshan area unique velocity structure not only plays a pivotal role in promoting horizontal tectonic stress during seismic activity, but is also the root cause of the aftershock evolution process and the fault’s morphological characteristics.

基于唐山及其周边地区47个固定和33个临时台站记录的4415次地震体波到达时间，利用稠度约束双差反演唐山断层的区域震源参数和三维精细速度结构模型。层析成像方法。结果表明，搬迁后的地震与断层走向大致垂直，最大深度超过25 km。唐山断层的面积Vp，Vs和Vp / Vs值显示出明显的不均匀性，而易碎断层的高速体在上地壳断层的两侧占主导地位。小的低速物体最初出现在Ms7.8唐山地震震源位于中地壳14-16 km范围内，随后低速区域随着深度的增加而逐渐扩大。唐山震源下方速度结构的变化表明，侵入地壳的高温地幔源削弱了上地壳的高速区，导致局部应力的积累，这是造成四川地震发生的重要因素。唐山地区。基于唐山断层的3D高分辨率速度结构成像，分析了近几年区域地震构造与唐山地震序列之间的关系，引起周边地块的迁移和地震活动。