By analyzing the forecast opinions and forecast data before the Mojiang MS5.9 earthquake,we found that the M ≥ 5.5 earthquakes in Yunnan are calm and abnormal,and the M ≥ 5.0 earthquakes have a continuous interval of more than 200 days. The small magnitude of the two earthquakes with M5.0 in Tonghai is a significant feature of seismic activity anomalies before the earthquake. The indication significance of the Tonghai earthquake and the precursory anomaly M ≥ 5.7 earthquake medium and M ≥ 5.0 earthquake short-term compre￣hensive forecast index is the main basis for judging the short-term risk of earthquake. Since 1900,the M ≥ 5.0 earthquakes in the 50km range of Tonghai has shown M ≥ 5.0 seismic superiority correspondence and the regional surface strain variation characteristics of GNSS characterization,which provide clues for location determination. The forecast experience and data of the Mojiang MS5.9 earthquake enriches our understanding of the complexity of earthquakes and accumulates new information for earthquake case study.