In order to comprehensively analyze the impact of the 2023 Pingyuan,Shandong,M5.5 earthquake on the surrounding area,we first determined the central focal mechanism of the earthquake based on different focal mechanism results:nodal plane I:strike 124.02°,dip 72.37°,slip -19.54°;nodal plane Ⅱ:strike 220.16°,dip 71.41°,slip -161.36°. The earthquake's focal mechanism aligns with the local stress field,indicating a normal energy release under the local tectonic stress field. Moreover,the relative shear stress and normal stress on nodal plane II exceed those on nodal plane I. Considering the NE-SW orientation of the active faults around the epicenter,it is inferred that nodal plane II is the seismogenic fault. Subsequently,based on the rupture model of the earthquake and a homogeneous elastic half-space model,we calculated the surface co-seismic displacement field,horizontal principal strain,and areal strain generated by the earthquake in the surrounding area. Our observations reveal that material to the north and south of the epicenter experienced uplift,while material to the west side subsided,indicating a distinct strike-slip mechanism close to the seismogenic fault. Compressional areal strain distribution was evident on the west side of the epicenter,whereas extensional strain distribution prevailed on the north and south sides. Finally,we computed the Coulomb stress changes on the main active faults around the earthquake. The results indicate insignificant Coulomb stress changes on the northern segment of the Cangdong fault,Liaocheng-Lankao fault's northern segment,the Gaotang fault,the Xuheixi fault,and the Chengxi-Fengerzhuang fault. However,the Coulomb stress unloading amount reached a significant magnitude of 1,000 Pa on the western section of the Qihe-Guangrao fault and the Linyi fault. The Xiakou Fault and the Lingxian-Yangxin fault exhibited the most significant increase in Coulomb stress,with a magnitude of 100 Pa,while the middle section of the Cangdong fault experienced both a maximum increase and reduction in Coulomb stress,reaching a high magnitude of 1,000 Pa. The area with substantial Coulomb stress modification in the middle section of the Cangdong fault warrants special attention regarding seismic activity.