Abstract: Based on the Mike21FM model, the hydrodynamic conditions of the artificial reef construction area and the surrounding sea area in Qianliyan West are simulated. The Euler residual current is calculated for 720 hours, and the residual flow velocity before and after engineering is calculated. The influence of engineering construction on hydrodynamic condition of surrounding sea area is studied. Furthermore, it provides reference for the study of the rationality of reef site selection, nutrient loss or enrichment area and water quality. The research shows that the resistance effect of engineering construction can reach 0.4 m·s⁻¹. The area where the current velocity increases during the period of surge is located in the north and south sides of the project area, with an area greater than 0.05 m·s⁻¹ of about 4.52 km²; The area where the current velocity decreases over 0.05 m·s⁻¹ is about 4.28 km². The mean decrease of euler residual current velocity in the project area was around 0.01 m/s, and the overall increase of euler residual current velocity in the surrounding sea area outside the project area, and the area with the maximum increase of more than 0.1 m·s⁻¹ appeared in the east of the project with an area of 0.41 km².