Abstract: Using the double difference positioning method, 1 402 earthquakes occurred on March 15, 2008 solstice and August 23, 2019 in the middle Shandong area are relocated, and the exact locations of 820 earthquakes were obtained. The tectonic stress field of 0.25°×0.25° grid in Luzhong area was calculated by using the composite focal mechanism method on basis of 5 048 P (Pn) wave initial motion symbols. The results show that the overall dip of the P-axis is small and it’s direction shows counterclockwise rotation characteristics: from north to south it gradually changes to NEE-SWW direction, while the T-axis direction gradually transitioned from NNE-SSW to NNW-SSE and the T-axis azimuth consistency in some areas is poor and the dip is large. Finally, the stress field characteristics of Jiyang Depression, Western Shandong Rise and Tan-Lu fault zone are analyzed.