Abstract: The failure have occurred many times at Wang Xia dangerous rock in the history,recently the two large deformation and damage of unstable rock have occurred in October after the rainy season,To explore the reason of the frequency of dangerous rock failure in the area,the authors assess different factors such as regional geological conditions,rain and structure of the dangerous rock,but also with deformation features of various sections of the dangerous rock and the monitoring data analysis.This paper indicates the origin and development of the dangerous rock is mainly dominated by the special geological environment and the free-face condition of the precipice slope,the continuous rainfall induced its re-occurring several times.Combined the monitoring data of October 21,2010 after the disaster,the trend of dangerous rock generally turned to larger deformation,the dangerous rock possible failure again,because of this the author used exponential smoothing forecasting model,According to the criterions of deformation and deformation velocity,the dynamic track prediction about the time of the danger rock re-occurring will be prediction,duo to the practical of the danger rock conditions,a model was established for the special displacement of the experimental validation of some observation points,and the prediction based on this model was achieved with high accuracy.Prevention of the dangerous rock for construction and the safety of the Yangtze River shipping has an important significance.