Aimed at the problems of insufficient targeted support, and difficulty in balancing safety and cost in the mining roadway of three soft coal seams, to guarantee roadway construction and long term service safety and optimize support investment, support parameter quantitative calculation formulas for roadways with various roof fall hazard grades were derived in this paper. Based on stable rock stratum identification technology and roof fall hazard grading system, combined with FLAC3D numerical simulation, the failure laws of roofs at different grades were revealed. A quantitative bolt cable support design method centered on roof fall hazard grading and targeted at risk prevention control was constructed. A quantitative reference standard for support design of mining roadways in three soft coal seams was established, and it was applied to the support engineering of W05 transportation gateway in No.B10 coal seam of Shajihai Mine. Long term monitoring verifications of deep and surface displacements of roadway surrounding rock were conducted. It was demonstrated that surrounding rock deformation was effectively restrained by this support scheme, the maximum deformation was controlled within 54 mm, deformation rapidly tended to be stable, and risks of roof fall and roof instability were fully avoided. The engineering practicability and scientific nature of this design method were verified.