Guardrails are an important ancillary facility of expressways. Accurate and effective identification of guardrails from road scenes plays an important role in high-precision map construction, automatic driving, road maintenance, and so on. At present, there are few research methods on guardrail recognition in highway scenes, and the existing methods have some defects such as low recognition accuracy and inability to distinguish guardrail types. In this paper, a point cloud of an expressway scene obtained by mobile laser scanning is taken as the research object. On the basis of the binary coding voxelization segmentation method, the clustering slicing method is used to recognize the guardrail target in the expressway scene according to the characteristics of the guardrail. In addition, a method for distinguishing the type of guardrail based on its cross-section characteristics is proposed to distinguish steel and concrete guardrails in a highway. The experimental results show that the proposed method can effectively identify the guardrail target in the point cloud of an expressway scene, and has high efficiency and accuracy.