To investigate the effects of loading methods in Brazilian Test on tensile strength for the PBX, traditional Brazilian Test, arc Brazilian Test and rubber-cushion Brazilian Test were conducted for PBX specimens, and the corresponding tension strengths was 3.57 MPa, 5.22 MPa and 5.48 MPa respectively. Compared with the tension strength of 5.5 MPa by standard tensile test, the rubber-cushion Brazilian test shows same result. The load-displacement curves of the traditional Brazilian test and the arc Brazilian test were invalid, but the load-displacement curve of rubber-cushion Brazilian test was valid. Small cracks appear at loading contact zones besides the leading cracks through samples by the traditional Brazilian test and the arc Brazilian test, but there was only one diametrical crack by the rubber-cushion Brazilian test. It indicates that the rubber-cushion Brazilian test estabilished by this work is better to measure the tensile strength of the PBX than the other Brazilian test methods.