Abstract: Artificial reefs placed in the sea with different layouts, would produce different flow field. The flow field of star artificial reef on different layouts and flow velocities (0.3, 0.5, 0.8 m/s) were simulated using the RNG k-ε turbulent model. The numerical simulation results are consistent with results observed in other methods. Therefore, the method of numerical simulation can reflect the situations of upwelling and back eddy around star artificial reef. With the increment of disposal space, the maximum velocity, area and height of upwelling increased and the back eddy area decreased in side-by-side arrangement. In tandem arrangement, the height of upwelling, the upwelling area and the back eddy area between two artificial reefs reached the maximum value at the 1.5 ratio of disposal space and the upwelling area reached the maximum value at the ratio of 1. The back eddy area increased with the increment of disposal space. The research can provide a reference for layouts and disposal space of artificial reefs put in sea bed.