Currently, the settlement of soft ground is measured using instruments operated by on-site workers. However, this method is expensive and inefficient in terms of data consistency, cost-effectiveness, and utility. On the other hand, surveying using unmanned aerial vehicle (UAV) light detection and ranging (LiDAR) is used in various fields. However, studies on its utility in soft ground are insufficient. Therefore, in this study, we examined the optimal method for creating digital elevation models (DEMs) for estimating the settlement of soft ground using UAV LiDAR survey data. This method involved selecting a coastal construction site as the study area and acquiring data through UAV LiDAR surveying. The acquired data were used to create DEMs through preprocessing and postprocessing. Settlement measurements obtained from on-site instruments and settlement estimates derived from DEMs created using various interpolation methods and grid sizes were compared and analyzed. Additionally, the utility of the created time-series DEMs in the settlement estimation of soft ground was evaluated. We proposed the optimal method for creating DEMs for estimating the settlement of soft ground and suggested methods to utilize the proposed time-series DEMs. Our research results show that the use of UAV LiDAR survey data can lead to the economical and efficient settlement estimation of soft ground.