The theory of the steel-plastic geogrid employed in supporting engineering is behind the practice, seriously affecting its popularization and application in engineering. Thus the tensile strength and deflection of steel-plastic geogrid and its control of surrounding rock deformations were studied and analyzed using laboratory and engineering field tests. We have contrasted the tensile strength of steel-plastic geogrid to that of metal mesh. We have also contrasted the deflection deformation of the steel-plastic geogrid concrete slabs to that of the mesh concrete slabs. In the tensile strength test, we have tested the tensile properties of three different types of steel-plastic geogrid. In the defection deformation test, two kinds of steel-plastic geogrid concrete slabs and the mesh concrete slabs are made to investigate the load and displacement they bear. By combining with the experimental application of the Wohu Mountain iron mine, we summarized the process of steel-plastic geogrid construction and monitored the surrounding rock deformation of test section. Thus, we drew the following conclusions: (1) the tensile strength of the steel-plastic geogrid was greater than metal mesh; (2) compared with metal mesh concrete slabs, steel plastic grille with concrete slab had a larger deflection and its stress tolerance ability was better; (3) the use of the steel-plastic geogrid supporting in roadway can control the deformation of its bottom and sidewalls.