Abstract: The analysis of paleo-water depth is of great significance in fields such as paleo-environment reconstruction, basin analysis, sequence stratigraphy studies, reconstruction of ancient landform, and the evaluation of source, reservoir, and cap rock conditions. Paleo-water depth analysis methods usually include paleontological, sedimentological, geophysical, geochemical, and digital simulation methods, each with their own strengths and limitations. Although some methods have advantages in a specific geological background, there are some deviations between different methods in reconstructing paleo-water depth in the same environment. These methods are mostly qualitative, easily restricted by natural conditions and require the samples of high reliability, which limits paleo-water depth research to a certain extent. Therefore, when analyzing paleo-water depth, it is suggested to comprehensively consider various factors such as geological background, environmental evolution, geological characteristics, and geological data, and to adopt multiple methods to study mutual constraints, in order to jointly explore the law of Paleo-water depth variation in the target layer.