The invention provides a low-frequency line spectrum detection method based on damping parameter matching stochastic resonance. The method comprises the steps of collecting a sound signal in an oceanby using a sonar, constructing a first-order damping nonlinear system, estimating noise intensity by using a maximum likelihood estimation method, estimating a noise variance for each reconstructed signal, matching a stochastic resonance numerical solution by calculating and setting matching potential parameters, searching an output corresponding to a maximum SNR value as an optimal output, inputting the optimal output into an energy detector, and giving a detection result. The method has the advantages that the low-frequency line spectrum detection method of the damping parameter matching stochastic resonance is given in the first-order damping nonlinear system, and the detection performance is greatly improved compared with a traditional energy detection method approximates an optimal matched filter in a Gaussian background.