A water-containing simulated lunar soil preparation and water content measurement system and method is provided. The system includes a water-containing simulated lunar soil preparation unit, a low-pressure environment simulation unit, and a water content analysis unit. The water-containing simulated lunar soil preparation unit includes a preparation pipeline, a low-temperature lunar soil cold trap, and a low-temperature water ice cold trap. Both ends of the preparation pipeline are connected with the low-temperature lunar soil cold trap and the low-temperature water ice cold trap through a first opening and closing valve and a second opening and closing valve, respectively. The low-pressure environment simulation unit includes a low-pressure pipeline provided with a vacuum pump. Both ends of the low-pressure pipeline are connected with the preparation pipeline and the water content analysis unit through a first pneumatic valve and a second pneumatic valve, respectively.