For the high-density resistivity method, favorable grounding conditions are required to ensure the establishment and measurement of the geoelectric field. Otherwise, unfavorable grounding conditions, like rigid pavement, will prevent some electrodes from being inserted into the ground, leading to the loss of valid data from standard observation devices and reducing the imaging quality. Therefore, this study proposed a method for the fast observation device design. This method supplemented data using an asymmetric quadrupole electrode array according to the spatial positions of missing data's recording points. Numerical simulations show that the method proposed in this study significantly improved the imaging effects of Wenner, Schlumberger, and dipole-dipole arrays, with a second-scale design time. In this study, an observation device based on asymmetric design for high-density resistivity imaging was successfully applied to the embankment detection in Ningbo, reducing the influence of motor lanes on data quality and accurately locating the embankment position.