Abstract: In order to solve the navigation jam and ship safety problems caused by excessive draft of inland ships, a ship draft measurement method based on ultrasonic phase control technology is proposed. In this method, an onedimensional linear ultrasonic phased array transducer emits the focused sound wave to perform phase control scan for the target ship to obtain the echo signal from each scanning point; then the matched filtering algorithm is used to improve the signal to noise ratio of echo signal, and the time delay of echo signal is extracted by threshold method; finally, the transit time method is used to calculate the arrival time of scanning point. The space coordinates of scanning points are calculated by hyperbolic intersection method, and the ship draft can be obtained by analyzing the amplitudes of echo signals and the position coordinates of scanning points. An experimental system for measuring the draft of small scale ship model is built to verify the effectiveness of the method. The experimental results of different drafts of 110~140 mm are analyzed, and the relative error between the actual draft and the measured draft is calculated. It is shown that the signal to noise ratio of the echo signal processed by the matched filtering method increases from 15.26 to 36.39 dB. The maximum relative error of the experiment occurs when the actual draft of the ship is 130 mm, the absolute error is 2.3 mm, and the relative error is 1.7%.