By analyzing the grille mechanical property, tensile strength and creep tests, and the field tests, we investigated the characteristics and the reinforcement principle of multidirectional geogrid, and obtained the effect factors of grid characteristics, load and time curve and the shear stress of grille and sand interface. The reinforcement effect of geogrid in combination of typical project cases was illustrated and the following conclusions were presented. Firstly, multidirectional geogrid has ability to resist structural deformation, node distortion or soil slippage under stress, and can effectively disperse load. Secondly, with the increase of tensile rate, grille intensity increases and the creep value also increases with the increase of load. Thirdly, the frictional resistance balance between horizontal thrust of damaged zone and reinforced soil in stable region can avoid slope failure due to excessive lateral deformation. Fourthly, the multidirectional geogrid is able to withstand the vertical, horizontal and diagonal forces by combing them well with three-dimensional orientation, realizing the purpose of preventing soil erosion and slope reinforcement, which has a wide range of application and development in engineering field.