At 2:33a.m. on August 6,2023(Beijing time),an M5.5 earthquake occurred in Pingyuan county,Dezhou city,Shandong Province. Shortly after the earthquake,the rupture process of the earthquake was quickly inverted using the data of the strong motion stations in the Shandong region built by the National Intensity Rapid Reporting and Early Warning Engineering Project. Based on the directional effect of the rupture,the main fault plane of this earthquake was determined through trend surface fitting. The inversion rupture model shows that the rupture plane is in NE-SW trend,and the rupture mainly extends from the epicenter to the northeast. The rupture duration is 8 seconds,the length of the rupture is about 8 kilometers,and the maximum sliding amount is 0.024 meters. The magnitude of this earthquake is relatively small,so the maximum sliding amount of the rupture is relatively small,and the rupture process is also simple. The distribution of aftershocks is in good agreement with the rupture area shown by the rupture model. The aftershock distribution near the boundary of the rupture area is also relatively concentrated,suggesting that the earthquake may be caused by the further release of accumulated stress energy.