Armor blocks are extensively deployed to shield vital coastal facilities against wave erosion. Evaluating the wave run-up and reflection under wave impact is essential for the engineering design of new ecological quadrangular hollow blocks. This study constructs a three-dimensional numerical model employing the open-source CFD software OpenFOAM-v2206 to analyze these processes for the new blocks. The model’s accuracy was confirmed by comparing its predictions with physical modelling tests. Model results accurately captured the variation in hydrodynamic parameters, as well as the energy dissipation properties of the new blocks. Sensitivity analysis indicated that both the wave reflection coefficients and run-up are considerably affected by mesh sizes, while velocity distributions and pressure fields were less affected by mesh. Finally, the model was utilized to examine how wave run-up and reflection for the new ecological quadrilateral hollow block are influenced by factors such as wave period, water depth, wave height, wave breaking characteristics, and wave steepness. The findings in this study provide valuable insights into novel design and safety assessment of new ecological quadrangular hollow blocks.