Abstract: Based on the foundation pit bracing for a particular red clay site on karst region in Guilin,with a limited retaining piles condition, proposed a method that the soil layer using reinforced concrete row piles while rock layer adopting micro steel tube pile, which can avoid the end-suspended piles, accelerate construction speed and save cost; starting from the forces analysis,check the bending stress and shear stress using section modulus equivalent and section area equivalent approach respectively,analyzing the displacement monitoring result of micro steel tube retaining pile. The research shows that soil layer using reinforced concrete row piles while rock layer adopting micro steel tube pile is feasible, which can effectively control the foundation displacement.