Abstract：We select the seismic catalog of Tengchong area in Yunnan province from 2009 to 2019, and use the Schuster test method to analyze the distribution characteristics of tidal phase angle of seismic activity. Combined with the corresponding relationship between seismic activity and lunar phase in 2019, we explore the possible relationship between seismic activity and astronomical tidal stress in Tengchong area. The results show a dominant tidal phase angle at the time when the earthquake occurred, with the P value far less than 5%. The occurrence time of seismic activity in 2019 also shows a certain correspondence with lunar phase; the lunar phase effect is more obvious when moderate and strong earthquakes occur. Both statistical tests reveal that there is a certain correlation between seismic activity and astronomical tide in Tengchong area; mainly shallower seismic activity is modulated by astronomical tides.