The flow structures around the tetrahedron -like penetrating frame and tetrahedron solid block were studied by using Acoustic - Doppler Velocimeter (ADV) for comparison purposes. The results indicate the velocity loss and turbulence intensity caused by tetrahedron solid block are larger than those caused by tetrahedron - like penetrating frame(TLPF) in the near field, and the former local erosion often happens around it. Contrarily, the variation in the velocity and the magnitude of turbulence intensity induced by tetrahedron-like penetrating frame issmaller. An integral method is used to derive the drag of TLPF. It is found that drag coefficient CD first increases and then decreases to approach to a constant with Re. 