Abstract: The vertical cable recording geometry is showing considerable promise as a seismic acquisition technology of marine exploration. Based on the ray tracing algorithm, the article adopts the method of bilinear interpolation on irregular cell boundaries and fast wave-front expansion to determine ray paths and reflection points on target layer. And the distribution density of reflection points on target layer is served as the key parameter to measure the acquisition geometry. The illumination analysis of marine seismic vertical cable is implemented by a series of experiments with the three-dimensional models of the seabed strata, shots, vertical cables and hydrophones. By the illuminating analysis experiment, the rules that the factors related the acquisition geometry affect the reflection point distribution are understood, which provide the basis for designing optimal vertical cable geometry and enhancing seismic imaging quality.