The "blood-water theory" originates from the water-vapor diseases section of the "Synopsis of Golden Chamber". The "three differentiation of Qi, Shui, and Xue" is an important content of the differential diagnosis of water-vapor diseases. The key pathogenesis of water-vapor diseases is "Qi leads to water stagnation" "water disease leads to blood stasis" and "blood disease leads to water stagnation". "Adjusting Qi to treat water", "treating water to treat blood" "treating blood to treat water" and "treating both blood and water" are important treatment principles based on the "blood-water theory" and have significant guiding significance for the treatment of gynecological diseases. The "blood-water theory" has unique characteristics and definite curative effects in the treatment of gynecological tumors. Classic prescriptions based on the "blood-water theory" such as cinnamon twig and poria pill, Chinese angelica and peony powder, and rhubarb and kansui decoction have achieved good therapeutic effects in the treatment of gynecological tumors. This article discusses the "blood-water theory" in the water-vapor diseases section of the "Synopsis of Golden Chamber" and its application in the treatment of gynecological tumors.