The characteristics of underwater ship wake bubbles and interference images under different water conditions by laser with high degree of coherence are studied, and the coherent figures with different depolarization angles are simulated. The simulation model of laser scattering detection by ship wake bubble clusters is based on Monte Carlo method. By the simulation, the intensity of multiple scattering is studied and the distributions of intensity received by forward and backward screens are also given. The Mach-Zehnder experimental platform is set up to detect underwater ship wake bubbles with coherent method in order to verify the veracity of theory and simulation. The results show that it is available to acquire useful forward-scattering information through coherent images. There are great differences among different water conditional coherent images which can be used to distinguish different kinds of water conditions, and further, different sorts of ship wakes. The research offers a new method to judge ship wakes and provides a new idea about ship wake zone detection.