Abstract: An underwater broadband near-surface source depth estimation method based on the frequency domain interference structure characteristics of the deep ocean bottom bounce area is proposed. In this method, the approximate expression of the output amplitude spectrum of the vertical array received signal beam is derived by establishing the structure model of the arrival sound field in deep ocean bottom bounce area. By utilizing the periodic oscillation relationship between the amplitude spectrum and the source depth and the vertical angle of arrival, the received signal is mapped to the depth-vertical angle of arrival domain, which can be used to estimate the depth of broadband sources. The validity of the method is verified by simulation and analysis of influencing factors. The results of the South China Sea experiments show that the depth estimation results are in good agreement with the actual source depths by using the vertical short array with 64 m to receive the double explosive bomb signals with calibration depths of 50 m and 100 m respectively, and the estimation error does not exceed 7%, which verifies the effectiveness of the method.