Seismic reflectivity inversion based on basis pursuit denoising produces sparse solutions through the application of l1 norm regularization. However, due to the presence of the regularization term, there is always a deviation between the solution obtained by basis pursuit denoising and the true solution. To reduce this deviation, this paper introduces the "residual addition" strategy in the basis pursuit denoising seismic reflectivity inversion, thereby improving the accuracy of the solution. The "residual addition" strategy uses a moderate trade-off factor to iteratively perform the Fast Iterative Soft Thresholding Algorithm (FISTA) to solve the objective function of basis pursuit denoising, and the residuals obtained each time are continuously added back to the original input. Compared with a single solution using FISTA, the solution obtained by FISTA combined with the "residual addition" strategy is closer to the true solution. In this paper, this method is applied to the Wen Chang Formation reservoir in the Huizhou Southwest Tertiary System of the Pearl River Mouth Basin in the South China Sea, and the calcareous sandstone and beach-dam sandstone are effectively divided through high-precision impedance inversion results.