By two-dimensional wavelet decomposition, the photograph texture of silty clay is analyzed in this paper and the multiple linear regression relations of the wavelet energy parameters and the traditional engineering properties of silty clays are constructed. During the image analysis, considering the requirements (such as light intensity, the distance between the camera lens and the section of silty clays) in taking images, colorful photographs of the clay were captured by a commercial camera in field investigation and transformed into grayscale images. The results show that these relations are much satisfactory. So the method developed in this paper may provide a new technique for quickly examining the engineering properties of silty clay in field.