The Direction of Arrival (DOA) estimation of coherent signals in co-prime arrays has become a popular research topic. However, traditional spatial smoothing and subspace algorithms fail to perform well under low signal-to-noise ratio (SNR) and small snapshots. To address this issue, we have introduced an Enhanced Spatial Smoothing (ESS) algorithm that utilizes a space-time correlation matrix for de-noising and decoherence. Finally, an Estimating Signal Parameter via Rotational Invariance Techniques (ESPRIT) algorithm is used for DOA estimation. In comparison to other decoherence methods, when the SNR is β8 dB and the number of snapshots is 150, the mean square error (MSE) of the proposed algorithm approaches the CramΓ©rβRao bound (CRB), the probability of resolution (PoR) can reach over 88%, and, when the angular resolution is greater than 4Β°, the estimation accuracy can reach over 90%.