This article discusses the application of single vector hydrophones in the field of underwater acoustic signal processing for Direction Of Arrival (DOA) estimation. Addressing the limitations of traditional DOA estimation methods in multi-source environments and under noise interference, this study introduces a Vector Signal Reconstruction Sparse and Parametric Approach (VSRSPA). This method involves reconstructing the signal model of a single vector hydrophone, converting its covariance matrix into a Toeplitz structure suitable for the Sparse and Parametric Approach (SPA) algorithm. The process then optimizes it using the SPA algorithm to achieve more accurate DOA estimation. Through detailed simulation analysis, this research has confirmed the performance of the proposed algorithm in single and dual-target DOA estimation scenarios, especially under various signal-to-noise ratio(SNR) conditions. The simulation results show that, compared to traditional DOA estimation methods, this algorithm has significant advantages in estimation accuracy and resolution, particularly in multi-source signals and low SNR environments. The contribution of this study lies in providing an effective new method for DOA estimation with single vector hydrophones in complex environments, introducing new research directions and solutions in the field of vector hydrophone signal processing.