In different versions of the directory,the 1856 Qianjiang-Xianfeng earthquake shows not a small difference on the epicentral intensity and magnitude. In this study,we gave a further collection of historical materials,consulting a wider range of historical records and local chronicles,and conducting a detailed analysis of the earthquake damage caused by it. Based on the field investigation of the Qianjiang-Xianfeng earthquake and the comparative analysis of several earthquakes in the southwest mountainous area in recent years,the possibility of the epicenter intensity is further discussed from the point of view of earthquake damage and the different intensity areas of seismic intensity map. We used several methods to estimate the magnitude of the earthquake. However,the determination of the epicentral intensity and magnitude of the Qianjiang-Xianfeng earthquake is still a difficult problem and needs further study.