The Mesozoic tectonic activity in Jiyang Depression is of great significance to the study of Mesozoic tectonic evolution in the eastern North China Craton. As a significant second-order tectonic unit within the Jiyang Depression, the Yihezhuang Salient provides a crucial window for studying Mesozoic tectonic evolution through systematic analysis of its fault activity patterns. Integrating geological and geophysical datasets with fault activity rate quantification, this study conducts a systematic evaluation of the YG991 Fault - a dominant structure within the Yihezhuang Salient - through stratigraphic throw analysis across discrete tectonic stages: Late Triassic, Early-Middle Jurassic, Late Jurassic, and Early Cretaceous. The results show that the activity of YG991 fault varies spatially along the strike. In terms of time, there are multi-stage changes, that is, the Late Triassic, the fault activity rate is negative, indicating that the study area was in the compressive stress field during this period, so the reverse fault developed. In the early and Middle Jurassic, the fault activity rate was still negative, but increased in the late Triassic, indicating that this period had a certain inheritance to the previous tectonic stress field, and the compressive strength was weakened. In the Late Jurassic to Early Cretaceous, the fault activity rate was positive and showed great changes, indicating that the fault was normal during this period, and the study area was in the tension stress field.