Abstract: Based on the seismic phase data from Shandong digital seismic network, the double difference positioning method was used to analyze those relocatable earthquakes in M4.1 earthquake sequence in Changqing, Shandong province in 2020. CAP waveform inversion method was used to calculate the focal mechanism solution of the main earthquake. The possible seismogenic structure of these earthquakes is discussed. The results show that the seismic sequence distribution converges obviously, the linear band feature is clear, the aftershock extends along the northwest direction. The focal mechanism shows that the earthquake dislocation type is comprised of both strike-slip and normal fault, which stretched in the north-south direction. Through the calibration test of this earthquake, we can preliminarily obtain the earthquake quick report strategy: select 5 ~ 6 stations close to the epicenter to determine the location of the epicenter, and use 10 ~ 20 stations within 100 ~ 200 kilometers to determine the magnitude. If time permits, more stations should be involved in the positioning as much as possible.