The invention discloses a method for testing grading broken stone CBR numerical value. According to the invention, a physical model and a mechanical model are established for simulating the grading broken stone CBR test, the method comprises the following steps: testing basic parameters, simulating of a CBR testing model, test pieces, a load plate, a CBR pressure head and the like, endowing the physical model with micro mechanics parameters, simulating a loading process of CBR test, finishing an arrangement of the simulation result to obtain the relational curve of the pressure head penetration rate and the penetration force, and obtaining the penetration force corresponding to a penetration rate of 2.5 mm according to the relational curve of the penetration rate and the penetration force. According to the invention, the grading broken stone CBR value can be rapidly and accurately predicted by the method, and a change rule of grading broken stone stress-strain can be represented.