Provided are a device and an experimental method for researching the insulating property of micro water containing SF6 gas. The device is mainly composed of a stainless steel tank, a micro sampling mechanism, ball valves, a micro water on-line monitoring system, and a constant-temperature heating unit. According to the method, the temperature and humidity of SF6 gas in the tank are adjusted by the device, so that the insulating property of micro water containing SF6 gas at different temperatures can be researched. The temperature and humidity of SF6 gas can be controlled accurately, and the reliability and accuracy are high. The device is simple in structure and convenient to operate, and can be widely promoted.