Based on the middle-small earthquake data in Anninghe-Zemuhe earthquake belt, 100 focal mechanisms of ML≥3.0 earthquakes are calculated. Using mechanical axis tensor method the direction of mean stress field of Anninghe-Zemuhe earthquake belt is given, with direction of NW-SE. The strike-slip earthquakes account for large proportion in all earthquakes and located in narrow areas. The plane and section of apparent stress are plotted after calculating parameters of source spectrum of small earthquakes. If relative high value area of apparent stress is thought as indicant of future strong earthquake risk, north segment of Anninghe fault and mid-north segment of Zemuhe Fault are the potential strong earthquake risk area.