Abstract: The triangular taper penetrating frame which was stratified by the height forms the flow around the three square columns to form an equilateral triangle arrangement. After the flow around the square columns, analyzing the features about distribution of the flow field and the lift and drag coefficients and the Strouhal number under the conditions of different spacing ratios was carried out in this paper. Within the limits of l/d=1.5~7 B and C column wake fields have experienced the process from near vortex mixing with near vortex separation and from far vortex mixing with far vortex separation. The B and C columns form flow around the square columns independently. When l/d=2, the average of the drag coefficients of each square column decreased significantly. And under the distance the slowing effect of water flow is most obvious; As a result of the existence of B and C columns and there is a great difference in the flow around a single square column: in terms of flow field in the l/d=1.5, B and C columns limited the furl of boundary layer shear zone of A. With the increase of distance this phenomenon will gradually disappear. On the dynamic characteristics, the drag coefficients of A column are lower than that of flow around the single square column. The Strouhal number Sr that increases along with the increase of spacing ratios is approaching to the Strouhal number Sr that was flowing around the single square column.