In recent years, in order to break through the dimensionality of urban planning limited to the ground floor, the number of large underground space projects is increasing, which makes a city gradually evolved into a "three-dimensional city". As a very important underground space facility, the underground ring road not only connects the adjacent underground space and ground space, but also effectively improves the traffic problems in the core area of the city. Taking a deeper underground ring road project as the starting point, the stress characteristics of different forms of single built and buried standard sections is analyzed from the structural point of view. In order to ensure its reasonable economy, under the condition of limiting the same mechanical parameters, the comparison of whether to add structural cavity in the underground ring road is carried out at the dosage level, which verifies the necessity of adding the cavity.