Abstract: Double-ring infiltrometer is widely used to combine with the Mariotte reservoir for measuring soil hydraulic conductivity. However, there are various kinds of measurement error and shortcomings using the traditional double-ring infiltrometer, particularly on unstable water supply, high labor intense when reading and recording of data. In this study, a new automatic double-ring infiltrometer was designed to improve the measurement precision, while reduce various sorts of errors. A fixed water level method was develop a low-cost and efficient automatic double-ring infiltrometer according to the measuring theory of hydraulic conductivity. The new-developed double-ring infiltrometer was mainly composed of inner (diameter of 17.6 cm) and outer rings(diameter of 30 cm), non-contact liquid induction capacitor level sensor (accuracy <1.5 mm), cylindrical water container, laser range sensor module (accuracy <1 mm), solenoid valve and other components. A non-contact capacitor induction liquid level sensor was selected for monitoring the water level, in order to keep the water level constant inside the both inner and outer ring. A cylindrical water reservoir was served as water source for the container of infiltrometer, and a sensor module with laser range was installed on the top cover of the reservoir. A laptop was connected the laser range sensor module to automatically monitor the volume of water supplied continuously. The combination of the high-precision liquid level control system with the non-contact inductive capacitive liquid level sensor and solenoid valves can be used to maintain a fixed water level in the water reservoir. Therefore, it is possible to increase the pressure difference of liquid level between the water reservoir and the double-ring, and thereby to make the initial rate of water supply in the double-ring infiltrometer much higher than that in the Mariotte reservoir. The new infiltrometer can match the initial rate of water supply, thereby to improve the measuring accuracy of hydraulic conductivity. The accuracy and reliability of the automatic double-ring infiltrometer were verified from July 2019 to October 2019, in the Lüyuan experiment field of China Agricultural University. The experiment was also performed on comparison between the new infiltrometer and the traditional infiltrometer with fixed water level method (double-ring combined with the Mariotte reservoir, collecting data manually). The field experiment results demonstrated that the stable hydraulic conductivity measured by the Mariotte reservoir was 0.068 5 cm/min, and the stable hydraulic conductivity measured by our new automatic double-ring infiltrometer was 0.068 7 cm/min. The data measured by new designed double-ring infiltrometer agreed with the theoretical infiltration model of Philip, where the corresponding R2 was greater than 0.99. In addition, the new double-ring infiltrometer can continuously and automatically measure the infiltration process, which significantly reduced error caused by traditional double-ring infiltrometer. The new infiltration measurement system can be expected to extend for automatic data sampling with high precision, and low cost, efficient, and easy to use in the field.