Water flooding reservoir fluid volume in extra-high water cut stage rises fast and moisture content predicted by using traditional methods is obviously different from actual moisture content. Conducted is study on change regularity of oil and fluid production in different reservoir water cut stages and study results show that liquid oil ratio is a sensitive factor affecting moisture content changes, moisture content rise speed will slow down with cumulative liquid production growth. Obtained is the binomial relationship between liquid oil ratio and fluid production according to the basic principle of characteristic curve of the water drive curve C type and derived is moisture content prediction model based on liquid oil ratio in combination with the relationship between moisture content and fluid production. Actual application results show that the moisture content prediction model has high accuracy and is worth popularization and application.