The invention discloses a rectangular square box breakwater structure, which comprises an anchorage (1), an anchor chain (2), a rectangular square box (3), a vertical-type outer-side wave stopping board (4), a vertical-type wave stopping board (5), an inner-side wave stopping board (6) and a wave stopping wall (7) and the like. A physical model testing device of the rectangular square box breakwater structure comprises the rectangular square box (3), a hoisting ring screw (8), a key ring button (9), a steel wire rope (10), a spring (11), a metal hook (12), a steel wire rope clip screwing off screw (13), an expansion screw (14), a foundation (15), a wave stopping board steel ruler (16), a board (17), a horizontal steel ruler (18), a slider (19) and a wave stopping wall steel ruler (20) and the like. The testing operation is concise, and the cost is lower. The rectangular square box breakwater structure and the physical model testing device are simple in structure, convenient to construct, strong in mobility, good in hydrophilism, less in environmental influence within a port, and are specially suitable for seas with larger water depth; and the wave dissipating effect is promoted to a certain degree.