It is a challenging task to segment drivable area of road in automatic driving system. Convolutional neural network has excellent performance in road segmentation. However, the existing segmentation methods only focus on improving the performance of road segmentation under good road conditions, but pay little attention to the performance of road segmentation under severe weather conditions. In this paper, an image enhancement network (IEC-Net) based on CycleGAN is proposed to enhance the diversified features of input images. Firstly, an unsupervised CycleGAN network is trained to feature enhance road images under severe weather conditions, so as to obtain an enhanced image with rich feature information. Secondly, the enhanced image is input into the most advanced semantic segmentation network, so as to realize the segmentation of the drivable area of the road. The experimental results show that the IEC-Net based on CycleGAN can be directly combined with any advanced semantic segmentation network and can not only realize end-to-end training, but also greatly improve the performance of the original semantic segmentation network for road segmentation under severe weather conditions.