Deep ocean convergence zones are important phenomena in marine acoustics, having a critical impact on the location of underwater targets. By exploiting the propagation characteristics of sound waves in deep ocean convergence zones, it is possible to effectively monitor and locate underwater targets. In view of this background, this paper proposes an underwater target matched-field localization method based on acoustic intensity in deep-sea convergence zones. The study first describes the research scenario of sonar sensors monitoring and localizing underwater acoustic sources. Next, it explores the characteristics of deep-sea convergence zones and details the construction of an acoustic field model using Bellhop. Subsequently, a method for estimating the distance of acoustic sources based on target signal intensity is introduced. This method utilizes the acoustic intensity obtained by sonar sensors within the deep-sea convergence zone acoustic field model and matches it with the measured intensity to estimate the target’s position. Finally, simulations were conducted to validate the method, and the results demonstrate that it can effectively estimate the distance of target acoustic sources, showing practical value in deep-sea acoustic applications.