Sand dike plays an important role in the sand-control system. In this research, wind tunnel experiments were conducted to simulate the protective effect of a series of sand dike models with different shapes, dip angles and heights. Results showed that:①Sand dikes affected the flow characteristics significantly. Five typical sub-areas in flow field around sand dike could be identified based on their flow characteristics: low-speed area before windward slope toe, resistance-confronting lifting area on the windward flank, mass flow accelerating area above the top of the dike, flow-sinking decelerating area of leeward slope and dissipating recovering area. The low-speed area before the dike and the mass flow accelerating area above the top of the dike could reduce wind speed and prevent sand transport. ②Considering the size of low-speed area before the dike body, the trapezoidal sand dike was better than the triangular one, but from the aspect of the effective shelter distance, the conclusion was just the opposite. ③The protective effect of the triangular sand dike reduced with the growth of the wind speed. The effective shelter distance of the triangular dike increased with the growth of the dip angle, while the low-speed area before the dike body decreased with the growth of the dip angle. ④The effective shelter distance of the triangular sand dike with a 40° dip angle was always the largest under four different wind velocities. ⑤The effective shelter distance on the lee flank of the sand dike was correlated with the height of the sand dike.