Accurate density inversion is the key to oil and gas prediction, which has been widely used in the offshore seismic exploration. The effect of prestack gathers optimization on the density inversion accuracy is discussed in the paper. Based on the prestack gathers quality evaluation and optimization, the quality of seismic data (signal to noise ratio, amplitude compensation rationality, and frequency difference) has been improved, the wide-angle effective seismic signals have been ensured, and gathers data fidelity has been improved. On this basis, the prestack three parameters inversion method has been adopted to obtain the density parameters for oil and gas prediction. Validated by blind wells, processed gathers data could effectively improve the density inversion accuracy, which will provide new means for oil and gas exploration.