1. College of Geo-exploration Science and Technology，Jilin University，Changchun 130026，China; 2. 31441 PLA Troops，Shenyang 110001，China; 3. College of Transportation，Changchun University of Architecture and Civil Engineering，Changchun 130699 China; 4. 31009 PLA Troops，Beijing 100088，China

The monitoring of water body change information is an important basis for the rational development， utilization and protection of water resources． The authors design a remote sensing monitoring method that uses factor analysis as a theoretical method to analyze the band sequence in multi-temporal remote sensing data to obtain dynamic change information of water body． Taking the water level drawdown of Taolinkou reservoir in QinhuangdaoCity as an example，and referencing to the“spectral characteristic time-phase change curves of ground object”，the changes in the spectral characteristics of various types of ground object in the study area were counted，and the factor analysis method of multivariate statistics analysis was used for quantitative analysis． Moreover，variance analysis method was used to test the significance of the dynamic recognition ability of each factor in extracting water body change information，factors that can accurately express the water body change information were then determined， and the water body change recognition index was constructed based on the water body change factor，so as to the dynamic change information of water body in the study area was obtained． The experimental results show that，under the reliability of 0. 05，there was a significant correlation between the water body change information and other ground object change information on the water body change factor，the water body change identification index based on factor analysis can accurately identify the water body in the study area，and there are fewer false detection areas，and the classification accuracy of water body change types reaches 96. 8% it shows that the method in this paper is a high-precision monitoring method that can effectively identify the dynamic changes of water body．