Based on the reconstruction and expansion project of Xingou Maoshi section in G240 Jianli County, this paper introduces the common types and characteristics of highway superelevation drainage, and studies the setting of discharge outlet of concrete guardrail in the central divider, longitudinal slope and transverse slope of the route. The size and spacing of the discharge outlet are determined through hydraulic calculation, and the influence of the longitudinal slope and super-high cross slope of the route on the setting of the discharge outlet is analyzed.