Field robot vision navigation is an important study field in complex scene, and widely used in military and intelligent traffic, etc. A new method of water hazards detection in the field environment is put forward based on polarization characteristic of light. It takes advantage of the physical principle that the light reflected from water surface is partially linearly polarized and the polarization phases of them are more similar than those reflected from the scenes around, and water hazard region of image is divided. The experimental results show that this method is suitable for water hazards scope detection and muddy region detection in complex natural environment. Compared with traditional robot vision method, polarization vision method has advantages of simple calculation, high accuracy, and it is widely used combined with existing image technology.