Aiming at the problem that the passive positioning of long-distance targets (such as submarines, torpedoes, etc.) is affected by Marine environment noise and ship's own noise, which leads to the reduction of positioning accuracy, this paper proposes an enhancement method based on convolutional denoising autoencoder and adaptive least mean square error filter (CDAE-LMSAF). By extracting the time-spectral features of the underwater target radiation signal and the noisy signal, it is trained and modeled as the input of convolutional de-noising self-coding. Then, adaptive filters are used to optimize the audio after neural network enhancement to realize the enhancement of underwater target radiation signal. The simulation results show that when the SNR is -5 dB, the SNR of the proposed method is 17.51 dB. Compared with 1.23 dB of multiwindow spectral subtraction, 7.21 dB of convolutional denoising autoencoder and 4.12 dB of adaptive least mean square error filtering, the proposed method has a higher SNR gain.