Rectangular frame-type artificial reefs can be employed to modify flow fields, providing favorable habitats for various marine organisms. In tropical marine areas such as the offshore waters of Hainan Island, they can also serve as attachment substrates for coral restoration. Flow velocities at representative measurement points of rectangular frame-type artificial reef models were measured using an acoustic Doppler velocimeter (ADV), and typical flow field characteristics around the reef models were further measured using particle image velocimetry (PIV). Based on the RANS equations and RNG k-ε turbulence model, the hydrodynamic field of a single rectangular frame-type artificial reef under different incoming flow velocities and flow incidence angles was numerically calculated and validated through experiments. On this basis, the flow field effects of multiple reefs under different deployment configurations were computed and analyzed. The results demonstrate that: within a certain range, the upwelling and wake vortex volumes of a single reef increase with increasing incoming flow velocity, and the flow field effect is optimal when deployed at a flow incidence angle of 45°; the flow field effect is optimal when the reef deployment spacing is 2.5 times the reef length in the longitudinal direction and 1.5 times the reef length in the transverse direction; when reef groups composed of multiple reefs are deployed linearly, staggered front-to-back arrangement of reef rows yields larger upwelling and wake vortex volumes, resulting in superior flow field effects.