Abstract: The parameters of anchoring bolt are very important for anchoring effects. Orthogonal optimum design is an effective method for anchoring bolt. Anchoring parameters of slope of Dawu section in Jingzhu high way are selected using orthogonal design principle. The results show that the effects of anchoring parameters are different and remarkable according to horizontal deformation of slope. The order of the difference is: the effect of anchoring bolt length the interval of anchoring bolt thickness of sprayed concrete. The optimum parameters, i.e. it's the length of the anchoring of 3 m, the interval of the anchoring of 2 m and the thickness of concrete of 100 mm, are obtained.