Semantic segmentation is an important method to interpret the road semantic environment. The convolution, pooling and deconvolution in semantic segmentation of deep learning result in blur and discontinuous segmentation boundary, missing and wrong segmentation of small objects. These influence the outcome of segmentation and reduce the accuracy of segmentation. To deal with the problems above, a new semantic segmentation method combined semantic boundary information was proposed. Firstly, a subnet of semantic boundary detection was built in the deep model of semantic segmentation, and the feature sharing layers in the network were used to transfer the semantic boundary information learned in the semantic boundary detection subnet to the semantic segmentation network. Then, a new cost function of the model was defined according to the tasks of semantic boundary detection and semantic segmentation. The model was able to accomplish two tasks simultaneously and improve the descriptive ability of object boundary and the quality of semantic segmentation. Finally, the method was verified on the Cityscapes dataset. The experimental results demonstrate that the accuracy of the method proposed is improved by 2.9% compared to SegNet and is improved by 1.3% compared to ENet. It can overcome the problems in semantic segmentation such as discontinous segmentation, blur boundary of object, missing and wrong segmentation of small objects and low accuracy of segmentation.